questions:
is there somewhere i can dl linux free with no **** attached?
can someone talk one on one about kernel to help me learn it?
if i use linux on my current comp will i be able to switch back to xp and still be able to use my files with no problem?
Linux is open source and open source is naturally free with no strings attached.
I don't know much about using Linux, so I probably can't teach you anything you couldn't find out yourself in the same amount of time.
You can multi-boot your installed OS's as long as they have their own partition; your files shouldn't be affected. I'm not saying that it's a definite answer because the way you set it up or even the OS you use could give different results.
A simple Google search usually gives you all the resources you need in the first few results and Wikipedia can probably answer just about all your questions about which distributions exist and which is right for you.