Could someone please point me in the right direction for resources where i can learn how to build a secure website for when customers make transactions using credit card?

I have little web design knowledge but am keen to start up a retail website.

Having little HTML / CSS knowledge, and attempting to set-up a retail e-Commerce site is a disaster in the making ... spend a good 3 - 6 months creating websites in those 2 languages first.

Another option is to use one of the readily available shopping carts and incorporating it into your site. To insure secure transactions you'll need to purchase a secure sockets layer (SSL) certificate as well and use https instead of http on the pages where security is an issue.