How do I get an object to spin properly in my animation? So basically I have a sphere that is tilted over at 90 degrees, and the rotation doesn't come out clean. I hit 5 then 3, and the cursor and all that is set to center, and when I click R then 90, the end result is fine but within the animation it comes out all wonky and doesn't do a clean spin or rotation properly (I want it to simulate an orbit, without moving the space station directly above it.)

Here is the file if you wanna take a look at it. https://www.mediafire.com/?13lr815jb51ws0t
More reliable way of rotating the sphere on exactly the axis and degrees you want is to select it, then press X (or Y or Z depends on what axis do you want it to rotate) then type 90 (or other number of degrees you want it to rotate). Then proceed as usual with key frames and so on.
And here is what else you can do in your particular situation.