I have a trek 8000, and the wheels on it are slightly bent (untrue) I'm not sure if its the thing that holds it onto the fork/frame is loose or if the rim itself is bent. Its not bad enough that it touches the brake pads although is could be that bad if I keep riding it like this. How much would it cost me to get this repaired? (IF it can be repaired) or is there a way I can repair this myself?
Look up wheels and bearings - the tools for either of these adjustments are not expensive (spoke wrench and cone wrenches). You dont need a trueing stand as you can use the frame as one - either hang the bike up or turn it upside down.
I had a trek 8000, what year? Mine was a 98. I remember those stock wheels were junk, always becoming untrue and very prone to damage from minor bumps. I had those wheels get much more untrue and bashed up than your sound. Some tools I use to fix, besides adjusting spoke tension, are a rubber mallet and a large adjustable wrench to tweak the rim itself back into position in damaged areas. Finally, one day, the rear rim separated from the rest of the weel and locked up against the brake pad. I went skidding and down to the bike shop the next day for some new rims. Sounds like you just need a truing. Take the wheel off the bike and the tire off the wheel and hold the hub and spin the wheel to watch where it's wabbling.
@EyeBike: My trek is from '91, I think (I'm not sure, it was given to me. God is amazing!) I set the bike upside down and spun the wheels again and it seems like just the back is slightly wobbly. The front looks fine (I thought it was wobbly, but I guess I was wrong) Not the bearings because they're tight, plus the bend seems to be at a certain spot instead of the whole rim.
I don't have the tools necessary for doing this myself, so i'm gonna spend $20 and get it trued (need a tune up anyway).