Setting up Exchange Server

I currently have a web hosting company host my website and email for me but would like to switch to managing it myself (one to save money, and two for the experience). I currently have a network consisting of 10+ PC’s connected to Windows 2000 Server which is the domain controller.

I want to have internal and POP3 mail (using outlook as the email client). I currently registered the web address envisionnetworking.net which of couse I would like to use (domain is named the same thing). I haveDSL Service for internet access also. Any clues?