WAIT!
If all you are doing is hosting a few of your own web sites, there is absolutely no reason to buy a server. That is overkill, especially if you don't know what you are doing.
There are companies that will give you a gig of space on which to host an unlimited number of domains for around $20 a month. With WebHostManager and CPanel to administrate it, you will have total control for not much money.
I do this now and have no real complaints.
And I concur with everyone else. I have used both, and much prefer unix to microsoft.