UNIVERSAL ANSWER TO THIS QUESTION:
Don't start a web host if you don't know what you're doing. You're bound to get asked higly technical questions, so buying a managed server or something would be much more fitting than making your own.
However, if you feel the need to do this... FreeBSD is really powerful, and really difficult to use in my personal practice. For the simplest server you can imagine, try SuSE and install ISPConfig using the package manager. It'll install all the pretty dependencies.
Of course I'll get yelled at for saying that, and I don't care at all. I'm right, you're wrong. :)