Your question asks primarily about the US Navy. I don't have the knowledge to discuss this fully, but can discuss how the Royal Navy introduced aircraft, and developed them into an effective weapon. There were more enthusiastic than the USN in many ways about the use of aircraft, but also benefited from more war experience, with aircraft of the Royal Naval Air Service playing a minor but capable role in the first years of WWI on land and at sea.

The Royal Navy's first chance to purchase aircraft came in 1907. Charles Flint, the Wright Brothers' agent in Europe, approached the First Lord of the Admiralty, Lord Tweedmouth, through an intermediary, Lady Jane Taylor. Flint was hoping to sell the RN a package of fifty two-seater aircraft, costing £2,000 apiece. While these aircraft were, for the time, quite capable, they had very limited range, just 30 nautical miles. The Admiralty decided not to purchase them, informing Flint that the aircraft "would not be of any practical use to the Naval Service". Instead, inspired by the successes of Count Zeppelin in Germany, the RN chose to pursue lighter-than-air aircraft - airships.

In 1908, the position of Naval Air Assistant was created on the Naval Staff, to advise it on new developments in aviation. A subcommittee of the Committee of Imperial Defence was also formed, to investigate the lessons of foreign experiments with aviation. This produced a report which concluded that aircraft were, at the time, not a mature system. Further experiments were needed, to prove their ability to operate at range, in inclement weather and over open ocean. Instead, it recommended the production of an experimental rigid airship. An airship offered significant range and loitering capability, allowing it to supplement a fleet's scouting effectively, making it much more capable than contemporary aircraft. The new airship, R1, was built at Vickers' yard in Barrow, under the direction of the RN's Captain Murray Sueter. She was not a success. It took two years to complete her, and on the first attempt at a test flight in May 1911, it was found that she was too heavy. A process of lightening was carried out, but when she was removed from her hangar in September to repeat the test process, she promptly broke in half. This spectacular failure led to R1 being given the name of Mayfly, and to the end of the RN's interest in rigid airships.

While official attention was drawn by airships, a number of officers began to experiment with aircraft on their own initiative. In 1909, a submarine officer, Lieutenant John Porte, designed and built his own biplane glider. Launched from a trolley by a crowd of sailors and civilians, it did take to the air on the 17th August, but crashed shortly afterwards. This was likely due to the unconventional control layout, with two pilots, one controlling yaw and the other controlling pitch and roll. This replicated the controls for a submarine, but did not work so well for an aircraft. The next year, Porte purchased a powered aircraft, but experienced a crash on take-off that forced him to abandon the aircraft. In 1911, he was invalided out of the RN following a tuberculosis diagnosis, and found work in the aviation industry. Sueter's deputy on R1, Commander Oliver Schwann, also purchased his own aircraft, an Avro biplane fitted with floats devised by R1's crew. Schwann spent his own money on the aircraft, but also collected donations from other officers working on R1, and their wives and families. Schwan would, in 1911, become the first person in Britain to take off from water, though he crashed shortly afterwards. Finally, in June 1910, Lieutenant G. C. Colmore became the first RN officer to hold a pilot's licence, getting training on his own initiative through the Royal Aero Club (RAeC). Several other officers would follow his example until Naval flying schools were available.

In 1911, the RN began its first official exploration of heavier-than-air flight. The rich aviation pioneer Francis McClean, who had paid for the RAeC's base at Eastchurch, had noticed that many RN officers and men from the nearby base at Sheerness were very curious about aviation. In early 1911, McClean left on an expedition to Tonga to observe a solar eclipse; he left permission for the Admiralty to use two of his aircraft, as well as securing the services of an instructor. The RN just had to pay for fuel and maintenance (and also chose to pay for further instruction in technical affairs). Four officers were chosen to become the RN's first flight instructors - RN lieutenants Charles Sampson, Arthur Longmore and Reginald Gregory and the Royal Marine lieutenant Eugene Gerrard. They went through the usual six week course of flight training, followed by an additional four and a half months of training that would give them a full knowledge of the state of aviation and flying at the time.

These new trained instructors gave the RN a core for training additional pilots, an effort which was bolstered by McClean's gift of ten acres of land next to the RAeC field at Eastchurch. However, they were equally significant for investigating new techniques and possibilities. In early 1912, inspired by the American experiments with launches from naval vessels, carried out by Eugene Ely from the cruiser Birmingham at anchor in Hampton Roads, Samson carried out the RN's first take-offs from ships. He flew from wooden flying-off decks built on the battleships Africa, Hiberia and London, flying back after each take-off to bases ashore. In September 1912, Longmore took part in a series of Army manouvres in Lincolnshire, providing reconnaissance for one of the two sides. At this point, British military aviation was largely under a joint Army/Navy force, the Royal Flying Corps, though the Navy had significant control over its Naval Wing. The exercise was a relative success, and inspired by these and the successes of seaplane carriers in other navies, the cruiser Hermes was converted to a seaplane carrier. Hermes joined the fleet in time for the 1913 Fleet exercises, where she operated well in the reconnaissance role. In this work, she pioneered the use of radios for aircraft and carried out the longest period of embarked air operations in any navy up to this time. Her success inspired the RN to build its first aircraft carrier, Ark Royal; specialised for carrying seaplanes, she was modified from a merchant hull and completed in 1914. The success also inspired the RN to take full control over naval aviation, forming the Royal Naval Air Service (RNAS) in 1914.

Most of this work had focused on reconnaissance, but the RN was also interested in aircraft as an offensive weapon. In early 1912, a Lieutenant Williamson suggested that submarines could be detected from the air, and that bombs could be carried to attack them. The former part of this was tested in June-September 1912 at Harwich and Rosyth, finding that aircraft could likely attack a submarine before it dived. Eastchurch, meanwhile was used for weapons development. At first, experiments were carried out with grenades and small bombs that could be dropped or thrown from the cockpit, but these proved inaccurate. Academic studies were commissioned to find the best possible designs for bombs and bombsights, while practical work on bomb carriers was carried out at Eastchurch. A gunnery officer, Lieutenant Clark-Hall, was seconded there to work on these experiments as a pilot, alongside Samson who carried out the early experiments - including dropping a dummy 100lb bomb. A major series of experiments in late 1913 showed that aircraft could drop live bombs without risk of damage from the blast. In 1912, a Lieutenant Hyde-Thomson wrote a paper describing the possibility of attacking targets with torpedo-carrying aircraft; he was soon sent to the Torpedo School in Portsmouth, to develop a torpedo that could be carried by an aircraft. A prototype torpedo was dropped by Squadron Commander Arthur Longmore on the 28th July 1914, though this was not exactly a practical weapon of war. The aircraft, heavily burdened by the torpedo, could barely make it off the water, while the 14in weapon was only really feasible for use against light targets. Other experiments were carried out to investigate the utility of aircraft for air defence, primarily against Zeppelins. These were a particular worry for the RN, both for their ability to strike effectively at British industry and because they could give the German fleet an advantage in scouting.

When war broke out in August 1914, a number of RNAS aircraft were deployed to France and Belgium. Some were used to provide reconnaissance for the Royal Naval Division, deployed to bolster the defences of Antwerp. Others were used to make strategic bombing strikes. Two aircraft were sent to bomb the Zeppelin sheds at Cologne and Dusseldorf. The aircraft heading for Cologne ended up bombing the city's railway station; the Dusseldorf attack was more successful, destroying Zeppelin LZ 25 and the hangar. Later, three aircraft made a successful attack on the Zeppelin factory at Friedrichshafen. As Ark Royal was not yet ready to serve, three Channel Ferries were requisitioned at the start of the war to serve with the fleet, carrying scouting aircraft for it - Empress, Engadine and Riviera. This decision was made because the existing battleships did not have the space to launch and recover seaplanes, nor the protected petrol storage and hangars needed to fuel and maintain them. The Zeppelin threat still loomed, though, and on Christmas Day 1914, the three carriers moved into position off the German coast. They launched nine aircraft against the Zeppelin base at Cuxhaven. Unfortunately, they failed to locate the Zeppelin base, but one aircraft unsuccessfully attacked the German cruisers Stralsund and Graudenz and another reconnoitred the German anchorage at the Schillig Roads.