Oscommerce not working

hi, im not exactly sure where the "right" place to post this is, but i think this will suffice. i recently setup an online shop for my borthers drumming company. i use oscommerce which comes usable with paypal. but whenever you go to pay for paypal, it only takes you to the paypal website, and not like an invoice, or a pay now page, or anything, just payapal.com. i tried posting at the oscommerce forums, but its pretty dead. can any of you help? or do you know where i can go for help? anything is MUCH appreciated. thanks ahead of time....