I have run my regular website for a couple years now - but last year decided to venture into the "e-commerce" world. The first thing you need to do is to get your website hosted (find a web-hosting company), and figure out what type of shopping cart system you want to use. I did lots of looking before settling on a cart.
Depending on who you host with, there may be several pre-installed cart systems that you can access at no additional charge.
I finally decided on an Oscommerce cart -
www.oscommerce.com - which is FREE. If you don't have a host, I recommend that when you search for one, look for one that provides "cpanel", with the "fantastico" module installed. I know that probably makes no sense to you, but you will see that offered on some of the various hosting company sites. What "fantastico" is - is a bunch of free software that is easy to install. If your host has it, then you can install the oscommerce cart in a matter of seconds with little or no computer knowledge.
Now.... the hard part is customizing your cart to make it how you want it. Fortunately, there are lots of places online that will help walk you through the process. You will need to come up with custom colors, themes, and graphics for your cart.
I learned rather quickly that accepting credit cards is a MUST. I personally needed to be able to process cards offline - so I purchased a terminal for my home (cost $350.00). The shopping cart allows the customer to input the card information - which is securely stored in the database, and then I just type in the card number, and other info into the machine. A "merchant account" is the name for your credit card processing account. Mine runs me $9.95/month, plus there are fees per transaction. If you decide to lease a terminal, or do phone transactions - this fee will vary. So will the per-transaction fee.
It is possible to set up your cart to automatically process the credit cards - and this is called a "gateway" account - but you're talking more money. I suggest you look for offline processing (such as your own machine or you phone in the transactions).
I also strongly suggest you accept
Paypal. About 1 in 10 of my transactions are paid for using paypal, and with it's recent integration with e-bay.... it is definately a plus to provide another option for payment.
Which reminds me. If you want a simple - very easy solution for selling stuff, look into starting an
E-Bay Store . I think it's about $10/month - but they host it, and provide the cart. Everything is very easy to set up, and you can run it with very little computer knowledge. It might be a very easy way for you to "test the market" without investing a huge amount of money in creating your site.
Anyway... if you want to check out my site (which uses the oscommerce cart), it is located here:
American Heroes Gifts .
Let me know if you have any questions and I'll do my best to answer them.
(Edited to add.... Here is a hosting company that offers the "Fantistico" software...
Lunarpages.com . I don't know anythign about them to recommend them - but you can see about what the cost is - and what you need to look for in a host by checking them out.)