I suggest you check out some of the sites set up specifically to assist webmasters, ecommerce operators and/or online retailers.
In any event, you'll need to be more specific about what you intend to sell, how you're going to acquire stock, how you intend to fulfil orders, returns policies, warranties, etc. and the minutiae of running a retail business, before you fill in the relatively small blank that is the online stuff...
-------------------- TFC 'Going to trial with a lawyer who considers your whole life-style a Crime in Progress is not a happy prospect.' - Hunter S Thompson (1937-2005)