Volunteer or grid computing are two ways to share computer resources with others in order to help work on a bigger project. These often have to do with research, on topics like medicine or the environment.
BOINC is an open source application with which you can connect to a number of projects and share your computer's resources. At BOINC's startup, it will display a list of all the projects you can participate in.
Select one or simply type in the url if it isn't included.
Afterwards, I'd suggest looking into the preferences to set BOINC to use your computer only when it is idle, such as overnight.
Don't forget to leave it connected to the Internet though.
There's three different views to choose from in BOINC, with the advanced one divided in tabs.
This will give you all the statistics on projects, messages, transfers and disk usage information. The best view in BOINC is probably the graphical one, which shows the frequency live in a multicolored wave form and data in a bar graph.
Overall, BOINC is easy to use, even if you don't have particular knowledge on volunteer computing. The only thing to watch is that the application doesn't use up too much of your resources, or to only launch it when it's inactive.
A nice way of sharing your computer's resources for the greater good, BOINC is easy to set up and provide lots of useful statistics.
