To expand on davratta's answer, Lidice – not a Prague suburb but rather a village close to the capital – was not the only place to be destroyed in reprisal for the assassination of Reinhard Heydrich. The small settlement of Ležáky also suffered the same fate after a resistance radio station was discovered nearby. All thirty three of its adult inhabitants were shot and all but two of the eleven children sent to the extermination camp in Chelmno.

In addition to Lidice and Ležáky, it is estimated that between two and five thousand people, mostly those suspected of aiding the paratroopers or the local resistance, were killed after Heydrich's death and the martial law that followed – the so called "second Heydrichiad", the first one being the period of reprisals ordered by Heydrich and resulting in 486 executions and 2242 people being sent to concentration camps.

Total Czechoslovak casualties during the war are estimated to be around 340 thousand with over two thirds of that number being Jews, and about 30 thousand military deaths, as Czechoslovak troops fought on both the western and eastern fronts.

But let's get back to the topic of resistance in Czechoslovakia. Shortly after the Munich agreement, several local cells mostly comprising former army officers started operating under the leadership of the ÚVOD group (Ústřední vedení odboje domácího) backed by the London government in exile. Another group, the communists, was also active during the occupation and helped and directed from the Soviet Union.

Although the efforts of local resistance were largely focused on intelligence gathering and minor sabotage, there were a few notable direct action outfits as well. The 1941 attempts at establishing such groups were unsucessful despite support from Britain, but this changed from 1942 onwards, with several operatives being parachuted into Czechoslovakia and helping build up small units and execute various operations, though none as high profile as Anthropoid.

The fighters also received Soviet support, and the 1st Czechoslovak Partisan Brigade led by Ján Ušiak was the the largest partisan outfit in the Protectorate during the war. Ušiak joined the Czechoslovak forces in the Soviet Union, and after receiving guerrilla warfare training, he and his men established the brigade in the Beskid mountains in 1944. Although Ušiak died later that year, the unit grew from its original size of about 300 partisans to about four times that number and afterwards worked with the Red Army advancing from the east.

As the war prorgressed and the notion of a German defeat became inevitable, there was a rise in resistance activity but also harsher and more successful reprisals from the Germans, with several resistance cells or partisan groups being destroyed completely. Any large scale efforts at military resistance were also hindered by geography, as the country lacked the terrain to hide significant numbers of fighters – with the exception of Slovakia, where such an event did take place.

In August 1944, the resistance in Slovakia launched what is now known as the Slovak National Uprising, but its initial success was short lived and soon the fairly numberous rebels (about fifty thousand strong) suffered losses and were forced to withdraw to the mountains, abandon their plans at large scale military resistance and only continued in guerrila warfare and sabotage.

Resistance efforts in Czechoslovakia then culminated in 1945. Generally speaking, the Soviet backed groups aimed to help the incoming Red Army, whereas their pro-Western counterparts focused on building up a resistance network to oppose the Germans. In spring, allied forces entered Czechoslovakia from the west, and the Soviets were on their way from the east, and in May a popular uprising was launched, with the liberation of Prague and Czechoslovakia following soon afterwards.

The most notable thing the Czech resistance did was Operation Anthropoid. On May 27 1942 they attacked a high ranking SS officer, Reinhard Heydrich, and he died from his wounds on June 4th. Heydrich was the chief of SS Military intelligence and was given a state funeral in Berlin. The SS retaliated by destroying the small Prague suburb of Lidice. 280 unarmed civilians were killed, the village burned down and the ruins were leveled. The covert agents that killed Heydrich were soon caught and Lidice was the only major Nazi atrocity inside the current Czech republic. It had a chilling effect of the Czech workers in the factories supplying the German military. Production slowed down and quality dropped off even more.
US Army Air Force ace, Francis Gabreski tells a story in his autobiography about finding an un unexploded shell, lodged in the armored seat back of his P-47. There was a piece of paper inside the 30 millimeter shell. Grabowski was a son of a Polish immigrant. He could make out the strange letters and sound out the words, but could not understand them. Two weeks later, while on a three day pass to London, Gabreski was able to show the note to a Czech RAF pilot. The note read "Sorry, this is all I can do for you now."
Sources: "A Fighter pilot's life" by Francis Grabreski and Carl Molesworth
The Lidice incident has inspired two history books, four novels and is the basis of three movies.