Ok I've got some newb questions maybe u can help me with. I have a simple Dell Pentium 4 Windows XP Home Edition pc. I don't game expect for xbox and ps3 and things like that so this is all new to me.
GPU's i get the basics that it is stronger then a cpu but I confused by all the add ons and want to know what the basic setup for someone like me would be. For someone like me how do I get started mining? Do I have to by all these different components or do I just need to rig a video card to my pc to get started and is a GPU another name for a video card?
Sorry if this is really basic and newbish but I just don't get what my first to should be and what I can expect will happen once it's taken. And and all help is very much appreciated.

First off, I don't
think that there's a whole lot of support for XP in the mining community. Just what I've read, haven't tried it myself. Most seem to use Windows 7 or Linux.
If you can get past the OS hurdle, the next step would be to add a GPU (aka Video Card). nVidia hardware doesn't work well with the requirements of BTC mining. AMD cards perform much better for the same investment.
Once that's added, you'll need mining software. Plenty to choose from. I prefer cgminer.
Lastly, you'll need to select a pool to participate in and set up and account. At this point, solo-mining by yourself would be like playing the lottery.
If mining is interesting to you and you just want to try it, then by all means go for it. If you think it's a "get rich" plan, then you need to do more research. Let's say that you invested the $400'ish in a new 7970 GPU, and conservatively let it run at 580MH/s, so that you can still use your machine for other things. That rate will find you about .02 BTC/day at the current difficulty.