Help: Rails/DNS Question

1) I'm just about to take the plunge of setting up and hosting a website off one of my own boxes in my room. The one thing I haven't had to deal with before is DNS. Is installing/setting up BIND the best alternative? What would you guys recommend?

2) Let's say I have a Rails app and 6 domains, each of which has a slightly different landing page. What's the best way to deploy things such that all six domains share the one app/db?

Thanks for your help!