Yar. Having them on normal is fine, but sometimes I've setprograms that use a lot of CPU doing something mediocre to below normal.

I really don't know much about how it works, but I've found it's risky having things higher than normal, since if they use loads of memory/infinite loop then it's pretty hard to have any cpu to do anything else (like shut them down).

What processes should be put on high priority? A friend said to put Explorer on real time, or high priority, and NetZero/Internet Explorer on high. Do you guys suggest this?

I set any application which doesn't have extended cpu spikes and shares cycles to high priority such as winamp or other media players. For games I'll set them to low priority to give background processes a chance since games tend to eat up all the CPU cycles they can get. Though you want to make sure task manager is either the best or tied for best on priority as nothing sucks more than when a processs stops responding and takes out task manager with it since the locked higher priority task is stealing all the CPU time from task manager. I wouldn't give Internet Explorer a high setting since if it blows up and stops responding on a site you'll lose control of everything that is lower priority. Setting explorer to realtime is a bad idea as that is higher than the default setting of task manager so if it crashes then you are screwed as you won't be able to kill the task from the task manager. Also if you are profiling something you will get more accurate results if the application has a high priority though don't make it higher than task manager so you can kill it if it locks up.

Though for the most part you shouldn't bother with the settings at all. The most common case in which I need to tweak the priority is to get games to cooperate with other applications. So unless I want to watch a movie on one moniter and play a game on the other I rarely run into cases in which I need to tweak the settings.