Maximum PC

I have been designing recreation/information websites for myself and friends for a while, but I am looking to start a small business website. It is mainly for my wife who wants to start a small arts and craft website. I am easily able to design the website, but I have never dealt with websites that have monetary transactions. What I am looking for is advice from someone who has gone through the same thing and found a great book that has helped them make the transition. I know there is an entire section on e commerce at BN but I am looking for first hand knowledge of a good/current book that will help me build a secure site. Because after all whenever one of us is thinking about buying something online the first thing we want to know is if the site is safe.