Start with submitting to tgp's (if you are absolute newbie). You can also try some AVS if you have some content. Amateurpages pays to Croatia, it's the best pay-per-click program.
EVERY sponzor will accept you if you make a profit for him
If you find some good sponzor don't accepting Croatien webmasters. Try to send them a mail and explain that you are no cheater and send them some samples of your webpages. That may help ( sometimes
). The best for signup and partnership are topbucks and nastydollars, but I think they both are not accepting East-Europe webmasters. But i'm from Slovak Republic and still deal with them
IF YOUR ACCOUNT IS PROFITABLE you will be accepted.
Flashcash and Flyntdigital are also good for signups and partnership.
If you are looking for a pay-per-mail sponzor use wegcash. They allow also remote boxes on your pages.