-Before taking the wheel out shift to the big front chainring and the smallest rear cog.
-Make sure the brakes are opened up before removing or reinstalling the wheel
-It's hard to describe, but when it comes time to reinstall the wheel grab the rear derailleur and rock it back with one hand to get it out of the way and to make it easy to bring the wheel in place
- Maneuver the wheel so that the proper part of the chain (above the top derailleur pulley and coming from the top of the front chainring) settles down onto the smallest rear cog (you didn't shift anything while the wheel was out right?)
- As you bring the wheel up into the dropouts make sure the tire doesn't jam into the brake which again should be opened up as wide as it goes.
That's about it for most bikes but some short chainstay bikes can still be a hassle and you just have to muscle the wheel into place.
-Dave