Pat,
Can you give a little more detail about what it is you are seeing/wanting to get rid of?
If you're not sure if something may be running (perhaps something that shouldn't be running), use the activity monitor to get the names of all running processes and google the ones you don't recognize. The first time our two you do this, there will be number of processes that you don't recognize that are part of the normal OS. After a few times though, you begin to recognize what's "normal" and only need to look at new/odd ones. IF there is something running that shouldn't be - a google on it will usually contain info on how to get rid of it.
Roger