I seen a pool that said Linux was the most popular Unix download. I then seen Redhat Linux is the most popular Linux download. Is there a difference? Is it the better program/s?

Linux is, for all intents and purposes, an open source flavor of UNIX.
Redhat is one distribution of Linux; others include suse, Fedora, etc.

Better Linux is a matter of preference and of your usage requirements. Redhat is essentially a commercial product. Fedora is their (Redhat's) freely available distribution now. Based on your original post, you may be interested in something like Fedora. It's geered towards a desktop user but can still be used for server-based applications.

So is Redhat a good one to go for? Are the basically the same with only minor differences or completely different programs?

Ok thanks, I think I am going to go for Fedora, mainly cause that is free

The Linux kernal is the baseline really. Companies like Redhat add their own extensions. I'm not sure that you can freely download Redhat anymore; you'll have to purchase a license for it.

By the way, ubuntu Linux has a bootable CD image that lets you try the distro before you install it on your system. This way, you can keep your Windows XP if you decide that you hate Linux; can't imagine that happening though.

Redhat allows you to download Fedora Core, which is the free version of its Linux software.
You probably want to start with a Live CD Linux OS, such as Knoppix.

You might want to do some more research. There are all different flavors out there and you should try as many as you can. There are some other great options like FreeBSD or OpenBSD if you want to go into the BSD style flavors. Don't forget about OpenSolaris now. Personally, I would just download Solaris 10. It is pure, powerfull and FREE. Best of all it runs on anything! sort of... Happy hunting.