Activity Monitor: How to know what processes to turn off?

Question

I cant seem to find something like a glossary for the processes that appear in Activity Monitor.
I get the idea for using the AM - to find out what processes are running and how much memory they are using, however, I just don't know what processes are "suspicious", uneccary, good, bad or whatever. Anyone know of some resource to help me know what I should turn off?
Many thanks!

Answer 1

Ah, in that case, watch your CPU usage.
When Activity Monitor starts, select either +All Processes+ or +Active Processes+ in the toolbar, and sort the list by the +% CPU+ column, so the highest numbers are on top, and select the CPU tab towards the bottom.
For this purpose, also select +View > Update Frequency > Less Often+ from the Menubar.
Various processes will "spike" up and down normally as they do things, then are idle, so you need to watch it for a while and get a feel for the processes that are using the most CPU, and the +% Idle+ at the bottom.
When the slowdown occurs, see if something changes significantly, especially if the +% idle+ goes to near zero. If that happens, see what process(es) are using the most CPU.
If the process(es) involved aren't familiar to you, post their names here (and/or check this out: http://triviaware.com/macprocess/all)
You may also want to select the +System Memory+ tab towards the bottom. Keep an eye on the total of Free and Inactive memory (if they're near zero, you may need more), and the +Page outs+ (if that's high, it's another indication you may need more memory).