New business bookkeeping question

[VeryTnA]

Let me start by saying that I am a "sales guy" I am just now learning the inner workings of business.
Last year I bought a few domain names. One of them I think I can build a business around. I went and registered the DBA so that I could open a checking account in that business name.
Now I have another (dot bomb) idea I want to start. I've already hired someone to build the site, buying equipment, etc.
Question is: Do I need to get DBA's and seprate checking accounts for each company. Can I run all my business through one account? I don't want to incorporate unless I have too.
Whats the best way to setup all this bookkeeping "crap" until I hire an accountant?