also how long did their service extend, did they fly all the way to Berlin?
The No. 303 fighter squadron was manned by polish expatriates that fled to Britain with the fall of France, they were the highest scoring squadron in the RAF at the heigh of the Battle of Britain so they did have an impact. Poland had 27 recorded aces flying with the RAF at the time of the Battle of Britain. The U.K., the Commonwealth and the Empire (and that is excluding aces or pilots that flew under their own nations colors rather than the RAFs) had many more and they outscore the Polish pilots by quite a lot on average. Poles, however, are the largest foreign contingent recognized by the British government, with around 145 men having flown with the RAF during the Battle of Britain out of a total of around 2,100.
Added aces during such an important period in the war is sure to have been helpful but the RAF didn't particularly need pilots during the Battle of Britain, contrary to popular belief. The Luftwaffe was running out of crews and planes far faster than the RAF and it was faulty intelligence on both sides that gave us the fabled "One more fortnight and Fighter Command was done". The British believed the Luftwaffe to be much larger than it really was and the Germans believed the RAF to be much smaller than it was and they seriously underestimated British fighter production capabilities.
All of the original Polish squadrons in Britain outlasted the war, one of them, the 300 Bomber, even bombed Berchtesgaden at the end of the war.
There were two Polish fighter squadrons, the 302 and 303 during the BoB, in which the majority of both pilots, officers, and ground crew were Polish. They accounted for 89 of the Polish pilots that fought in the battle. Both squadrons entered active service in August 1940, nearly a month after the officially marked beginning of the BoB. The 303 didn't have its first combat sortie until the end of the month on 31 August and then was transferred to a rest period on 12 October. In the 43 days they were active, the 303 claimed 126 kills, versus only 18 lost planes, 7 pilots KIA, & 5 seriously wounded.
When compared to other RAF squadrons in the BoB, only Spitfire equipped squadrons match up with the 303, despite the Polish pilots flying the somewhat less capable Hurricane. Most of the other high scoring squadrons also had longer periods of active service during the Battle.
Because of the Polish pilots' previous experience and training, they preferred tight formations and closing to short distances before firing on enemy aircraft. That's part of the reason they got the reputation for being fanatical and reckless. They also were willing to fire on German pilots who were parachuting out of their planes, which many of the British pilots did not like to do.
The 300 and 301 bomber squadrons were also active beginning in August during the BoB, and a couple more fighter squadrons went active near the very end of the battle. By the end of the war there were about a dozen Polish fighter/bomber/recon squadrons active in the RAF.
Primary Sources: Battle of Britain, Richard Hough & Denis Richards. A Question of Honor, Lynne Olson & Stanley Cloud.