well first of all you need to incorporate. that way if something goes wrong they will hunt your business not you. also you need a webspace, i dunno about the traffic and what excatly you are gonna do, but you can chose a nice hosting package from
www.freeservers.com from $2 a month. for payements i use paypal. it's secure and it has the best terms i've ever seen. to incorporate try
www.bizfillings.com . it was like $570 for ohio but they move very fast. the only drawback is the IRS which takes it's sweet ass time