Hi, BBS-
This Website (click) will give you some songs and carols, and Mamalisa has children's songs. Wikipedia has some.

I have three books of Polish songs, and all three are excellent. The one I like best is Treasured Polish Songs with English Translations, published by the Polanie Club of Minneapolis in 1953 (I have the 1978 edition). This book has 220 songs, and it's wonderfully illustrated. A used copy should cost you less than twenty bucks.

Easier to find is Merrily We Sing: 105 Polish Folksongs, collected and edited by Harriet M. Pawlowska (Wayne State University Press, Detroit, 1961 & 1983). Again, used copies are well under twenty bucks.

The third is called The Polish Heritage Songbook, published by Polish Heritage Publications in 1995 (originally published in Poland as O Moj Rozmarynie in 1988. This book is mostly military songs and has no English translations, so I don't use it much.

The first two books have served me well. Whenever my Polish wife and her mother can't fully remember a song they learned in childhood, I can usually find it and fill in the blanks for them. Christmas and Easter are particularly fun in our household, when my wife and her mother cook up a storm and sing Polish carols to each other. The rest of the year, they have to put up with my cooking and singing.

-Joe-