I am building my first website eCommerce site. I am building the site for my fathers store and am using using wordpress and the udesign theme, along with ecwid for the shopping cart. Do I need any type of software to make the site more secure because of credit card transactions?
One thing you will need is an SSL certificate. This basically protects the transaction from being "overheard". You can buy one from your hosting company and they aren't that expensive. Just a Quick SSL is enough but get it from an established provider like Thawte, Geotrust or Comodo. You will get less problems with browsers giving "Untrusted" notifications to customers but also it's more reassuring to see a "trusted" brand.
You should also look very seriously at your shopping cart to make sure it is fully up to date and patched and that you are using all recommended security settings. Think very carefully about securing those credit card numbers!
You might also want to look at security products like Sitelock or Truste. They are good for security but they are also very reassuring to your customers (I've seen studies showing that they bring in more money than they cost simply because customers trust you more).
Actually Magento is a very good shopping cart but not in a shared environment. It needs it's own server. You would need to go to a hosting company that supplies dedicated Magento packages that are on their own installation (Pinnacle cart is very good too). If you were looking for something to install into a shared hosting package I would recommend OScommerce (which is free).
Do I need any type of software to make the site more secure because of credit card transactions?
Taking payments on the internet is full of security problems, and not for novices. Use a third party payment processor such as PayPal, Google Checkout, World Pay or one of the other options available. You can find more information in the e-Commerce section of the forums.
I agree with TechnoBear. For a small on-line business, it doesn't make sense to do yor own credit card processing. Better to sign up with one of the big payment processors like WorldPay. They will cream a small slice off each transaction, but they will save you a lot of hassle, not to mention taking the whole security nightmare off your shoulders.
What kind of products are you planning to sell online?
How many different types of products?
Perhaps it's interesting to investigate using a hosted solution. So instead of downloading your software and setting everything up yourself, you simply pay a monthly fee and have all the hassle taken care of by people who know their stuff. For example, something like http://flyingcart.com/ (I haven't used them, so I can't endorse them, but their offering looks pretty good).
Actually "done for you" shopping carts can be a great idea. So long as your budget can stretch to them. But always look at the cost if you have to upgrade. Usually they have a payment tier where it starts low but the payments get much larger as your needs grow. Although having said that, if you are turning over a million dollars a year - paying a thousand a year for the shopping cart is not such a big deal. And they handle all the security, hosting, upkeep, etc, etc.
There are a few to choose from but I've heard good things about Shopify (but I haven't used them myself).