Convert website to work on wordpress, integrate database login to use wordpress member login

I have a website [login to view URL] and want to convert it to work in wordpress, I want to be able to use the wordpress member login and management with my current website. the task: 1. Current website and convert it to work with wordpress. 2. Be able to use the login and features with wordpress 3. no graphics are needed just convert to use 3 column template as i want to use wordpress widgets. current website uses php5 and mysql5