Pre-Newbie question: Domain names

[DedZed]

Hello all. GG&Jims's has been invaluable and I have learned a lot. I plan on moving forward in the next week with designing my first free sites.

Now my question...

I have noticed a lot of free sites reside as sub folders under a domain. So should I get one domain name and construct all my free sites underneath that domain? If so, what should I do with the top level domain page?

Any assistance with this would be greatly appreciated. That is if anyone understands what I'm asking.

DedZed