jsp User management / shopping cart

[SinNisTeR]

I thought about doing the backend of the site im working on (nothing professional, just for fun, to learn), but it seems like a lot of work that i dont know how to begin. Im running resin http server on apache with postgresql 8. Any good free shopping cart/user management system? or tutorials to get me started on my own?

 

[SinNisTeR]