Mouse buttons have weird functions

Should be able to check what's set already in the preferences for your trackpad. If you would like to customize them more, I would suggest looking into Better Touch Tool which allows you t fully customize a trackpad or magic mouse to do just about anything you could want from it. Not sure if the sites have been updated with it's specs as I think they still says SL only but I can confirm that it has been updated to work on Lion.

I've used BTT on both my macbook (for my magic mouse since I have the old trackpad) as well as iMac with my magic trackpad. The things you can set with it are nearly endless if you look into everything.