Best small office network design

I would like to know how to set up a network in two offices that are in seperate locations. I am thinking of using DSL to have remote acess to both offices, and to my home, where the server will be located at if that is a possible.I have cable internet at my home.I have two computers at one office and two at the other. I would like to use Windows XP Pro for the O/S. Any answers would be helpful. Thank you very much.
Michael E. Currera. E-mail address currera500@aol.com