I know a lot of people who feed birds don't like to have squirrels. After all, bird food is expensive and squirrels can be destructive. However, I love the fox squirrels. I enjoy watching their antics. As you can see in the photo to the left, they are very acrobatic, which makes it difficult to keep them out of your feeders. This is one of my resident squirrels casually hanging upside down and nibbling sunflower seeds that he removes from the wire basket to the right.
Baffles can help, feeders with cages outside of the feeders (providing the cage is more than "arms length" from the seeds) can help. Placing your feeders on a pole several feet from any structure a squirrel can stand on will also help (but most birds won't like being so far from cover either.) But as you can see in this famous You Tube video, squirrels are hard to discourage. Personally, I just plan to feed them so I can watch.
The squirrels love black oil sunflower seeds, as most of my favorite birds do. One sure way to reduce squirrel feasts at your feeder would be to stop feeding black oil sunflower, but be prepared for a drop in some nice birds as well. What fun would that be?
Squirrels often bury nuts to find later when the weather is bad and food is scarce. How do squirrels find their nuts again? There's a nice short video on YouTube on an experiment on nut finding behavior in squirrels you should find interesting. If you just want to watch something silly (people will do almost anything), then check out squirrel fishing. The squirrels aren't all that funny--it's the numbskulls in the tree.
Anyway, enjoy your squirrels--chances are you won't get rid of them.