Hi jimmy99james. First of all, Welcome to Mac Forums!
Secondly, you MAY not have a problem. Fonts on Macs are intentionally smoother and rounder than they are on PCs or on Linux. For a comparison, see my Linux to Mac Switcher's Guide at:
http://www.campbell-tx.net/MacOSX/Linux2Mac/linux2mac.html
and scroll about half way down to the section entitled "Font Rendering". Have a look at the three screen shots. Does this accurately represent your problem perhaps?
If you coming to Macs from Windows or Linux, you will notice that fonts just don't seem as crisp. Unfortunately, there isn't a lot you can do about it. My guide does mention a few things, but in the end, this is a style decision by the Mac team. Love it or hate it, that is how Macs are.
Now let me stretch my credibility a bit. As you can probably tell, I came to Mac from Linux and I was more than just a little distressed at the font rendering on Macs. That was the genesis of the section in my guide. The "stretch" part is this - after a while on Macs, you will start to *like* the smoother rounder fonts. These days, I really notice the jagged edgy fonts on Windows and don't like them nearly as much. This takes time though - at first I was honestly appalled. I decided that the tradeoff of "muddier" looking fonts was worth it to drive a Mac, but I was not happy about it. Over time though, this disappeared, and I really like it now.
If your font rendering look significantly worse than what you see in the screen shots in the guide, let us know. Else, follow the guide's (minimal) suggestions for tightening up the font rendering and grit your teeth and live with it for a bit. You may find you like it after a while...