How to install Asterisk™ - the Open Source PBX!

Hi All

Can anyone tell what is the hardware and software required to run the asterisk PBX.

I need to know step by step procedure to install Asterisk™ - the Open Source PBX!.

After installing the PB do i require to tie up with voip company to make overseas calls.

Wating for reply.
Thanks

Hi, check there:
voip-info.org/wiki-Asterisk