Building an e-commerce site

Hi everyone

I'm entering a project to setup an online hardware store. I have a recent degree in CS (not Counter Strike :P ) and some php programming experience, but never been in this kind of project before. So i'm not sure about the software to use and such.
The idea as of now is to work with an apache server with php and mysql as the database. The design and implementation will probably be done on WinXP but, and as everybody, i guess, the budget is tight so i'm wonderin about good tools that are free (woohoo) and as efficient as possible.
Any help about good software, efficient site and database design, and any other related stuff is very much welcome.

Thanks.

Are you looking for a package of some sort? I've used zencart and oscommerce with some success. They both can install 'out-of-the-box' or be customized. Zencart is a bit speedier on the systems I work with, so I've come to prefer that, although it does require a bit more skill with php/mysql (but it's always good to learn).

I've played with a few others, even built a simple catalog, but those are free and the customization was simpler than building one.

Thanks for the tip NotGoddess, i just discovered OSCommerce before your post but wasnt aware of zencart, which aparently rocks, in a zen sort of way, of course
I thinks these packages are the best way to go, cause i'm doin it all alone and starting from scratch might be a bit overwhelming. Especially zencart, a very customizable little toy from what i saw.

Thanks again for your help.