When you want your web site to be e-commerce enabled there are two distinct systems to consider: the shopping cart and the payment gateway.
Shopping cart software is named for its similarity to the real-life supermarket shopping trolley. It allows your customer to browse around your web site collecting items to buy or putting them back. The shopping cart program provides links to add items, change quantities or put them back, and remembers what the customer has chosen even if he leaves the site and returns later.
There is a huge range of shopping cart software available depending on your requirements and budget. Some of the best open source (free to use) programs are included for easy installation via your hosting control panel (details).
These are web sites that specialise in taking credit card details online. Typically your shopping cart calculates a total bill and passes the customer on to the gateway site to process their credit card. While it is possible to request this information via your own site we strongly recommend that you don't - a shared web server is simply not a suitable place for storing credit card information. Likewise you should not ask customers to e-mail credit card information to you. If you really want to process payments on your own server then a dedicated server should be used only for this purpose (this is a very expensive solution!).
You should first contact your merchant provider to determine which payment gateways they will accept. If you don't have a merchant account there are some gateways that will still allow you to take credit card payments, see for example Paypal (now accepting payments in Au$) and Paymate (an Australian business offering a similar no-merchant-account service). Typically the percentage fees for these services are high but fixed and setup fees are low, so when you're starting up they can be great value but once your credit card income grows a merchant account will be more economical.
Most users now understand the importance of the little padlock symbol in their browser - sensitive data is being encrypted for it's journey from their computer to your server. You can make your web pages secure either by using the server's shared SSL certificate (at no charge) or purchase your own certificate. You may prefer to use your own certificate so that visitors see only your business name and not the server name, but this comes at extra cost - the price of the certificate itself ($100+ per year) and an additional $2 per month hosting for a new IP address - each address can have only one SSL certificate. There is no difference in security between using a shared certificate or your own.
We can help with all aspects of selection, purchase and setup of e-commerce systems, please contact us for details.