How do I determine what programs are running in the background and how do I turn them off? Are these the same as the things listed under Processes in the Windows Task Manager?

Basically yes.

The best way to manage these is to adjust what start on system start up.
A good application to help with this is CCleaner.
This cleans your system of junk files, cleans registry and can be used to control start up programs.
Best of all it's FREE.
Available here: CCleaner - Home

Are these the same as the things listed under Processes in the Windows Task Manager?

Yes, there are also services running that may not show up in taks manager, do you need to stop something in particular