virtual servers

hi there

am really after advice. i would like to install vmware so i can have a virtual operating system on my pc without having to physically set up (e.g) windows 7 on a physical drive. can you give me some tips on what i need to do in order to have this a reality?

am after a way of getting a virtual server built with windows 7 so i can install and test software. i understand that if i need to set a partition of for instance 20GB i can but then use the virtual host set up to install my windows7.

any tips greatfully recieved

cheers