I am a teacher and have a Polish boy starting in my class with no english (age 5).
This book could be really useful to give you a basic start on many words ... I bought it for my friends two kids, who had no English when they arrived here. The older one is doing OK now, although he hates to speak English at home.
milet.com/detail_english.asp?lang=Polish%2DEnglish&ProductID=409
I'd also suggest that if you can have a word with his parents, and ask them to let him watch English children's TV at home, as he'll pick up language from there too. I know of a few Polish families here, who have got Polsat installed (the Polish version of Sky), just so their kids can watch Polish cartoons (or CBeebies dubbed into Polish). Personally I don't think that helps the kids at all, as it gives them no incentive to learn English.
Hope that helps....