Animation is *everywhere* in OS X, and it is not possible to disable *all* animation with one global setting, which makes this a very complicated question to answer completely.

I would advise you to try disabling things one at a time as you find animations that annoy you.  Check System Preferences to start.  For example, the Dock magnification animation can be turned off in System Preferences -> Dock.

Also, check out [TinkerTool][1], which allows you to do the following:

 * Disable the animation effect when opening files in the Finder
 * Disable the animation effect when opening information panels or Desktop icons
 * Disable the animation effect when selecting information categories
 * Accelerate the animation of opening and closing sheets

If there's an animation that really bugs you and you can't figure out how to disable it, try posting a separate question here at Ask Different for that specific issue -- you will get a fast and accurate response.  (And as a nice side effect, both you and the people helping you will earn more rep that way.)


  [1]: http://www.bresink.com/osx/TinkerTool.html