How to Establish VPN Server ?

Hello, im a new MIS Staff here in our company, and im the only tech in my department.. and i have to work even if im at home.. so i have this idea by putting up a VPN connection. im planning to establish a VPN Server in our office running in Windows 2003 R2 so i could connect to our network resources when im at home and also for real-time support. our network is behind a firewall and also i have a router.. can anyone could give a expert technical advise.. please do so.. thank you very much..