Hello

I read about the GET and POST commands, but am Having some trouble with them.
I know how to use them but in just their simplest form, EX:

GET www.any.com / http 1.0/

But I need a more in depth look at using these commands, and possibilites that can be done using these commands. Either a reply w/ an explanation, or if anyone knows a few good links about these commands, that will help.