How to exclude files from Time Machine backups

[iMore.com]

Sometimes you don't want Time Machine to back up your files. Here's how to keep that from happening.
Time Machinee, Apple's built-in backup utility, is actually pretty smart about figuring out what to save and what to skip on your Mac. OS X by default excludes a whole bunch of stuff from Time Machine that Apple engineers know the Mac just doesn't need in order to work right after restoring from a backup. There are times, however, when you might want to make it a bit smarter. It could be big but temporary files that would just eat up space, or private files you don't want duplicated anywhere, even for back up. Either way, with a few simple tweaks, you can more storage capacity out of your Time Machine backup disk and spend less time backing up, too.

Full story from the iMore Blog...