OP, if you are writing about Poland during World War II (or former Polish resistance fighters after the war), I cannot recommend highly enough Halik Kochanski's book The Eagle Unbowed: Poland and the Poles in the Second World War. It's the best, most effective, and most compelling-reading book to grapple with the really tough history, historiography, and modern politics of the Polish experience(s)--Christian and Jewish, in and out of Poland, under the Nazis and the Soviets--in WW2. Seriously, it's a genuinely good read in addition to being excellent history.

That said:

Kochanski of course covers Operation Barbarossa from the Polish perspective. She notes a few things that are worth considering:

• Many Polish people knew something was going to happen, since German preparations to invade the USSR typically happened in Poland
• Much of the initial invasion of Soviet space wasn't the USSR itself, it was occupied Poland. That is to say, a lot of the fighting took place on Polish soil. As Soviets retreated, they often tore up and stole Polish property even more than they already had. In some places, they committed mass murder, especially of current prisoners, on their way.
• From letters and memoirs by Poles living in the formerly Soviet-occupied territories, we know that they were pleased by the invasion. But not quite for our modern "never get into a land war in Asia" jokes. Indeed, the expectation seems to have been mostly that the Nazis would actually defeat the Soviets! (Remember, the USSR are serious, serious bad guys to the Polish Christians and Jews who had suffered and starved and been murdered under them). However, they hoped that the victory would weaken and divde the Germans enough for the western Allies to dig in their claws and defeat the Nazis in the end

After the Germans consolidated their hold on all of Poland, there was a month or so gap where things settled into a 'new normal,' maintaining the local Polish shell administrations. This was over by August, and the situation for Christians and especially for Polish Jews deteriorated rapidly.

Again--Kochanski's book is fantastic; I really hope you'll check it out!

I don't have any source that would state it certainly but I think it would be reasonable. There's a book by Miron Białoszewski "Diary from Warsaw Uprising", so it isn't 1941, but it is said there that Polish civilians, so there aren't resistance fighters, celebrated every more serious attack towards Nazis. There you go with a random quote in Polish: A co z frontem? Sowieckim - tak się wtedy mówiło. (...) Więc chyba z 9 na 10 września —pierwszy nalot na niemieckie dzielnice. Zrzucanie lampionów; tych, co tak się kołysały i oświetlały długo, długo wszystko, że można było igłę znaleźć na ziemi (...) Pamiętam huki. I błyski. Wszystko to blisko nas. (...) Aż wylecieliśmy na ulicę z radości.

Aaand there goes my kinda weak translation since Miron Białoszewski uses very weird language (that's also a reason why I skipped some parts, there were unnecessary to get my point). So what about the front? So it was, I think, on the night between 9 and 10 of October – first bombing on german districts. Throwing off lanterns [Miron calls everything his own names, that's obviously kind of a bomb], the ones that swayed and illuminated everything for a long, long time, that let you find a needle on the ground. (...) I remember bangs. And flashes. Everything so close to us. (...) We even jumped on the street from happiness.