What do I need for an full business network setup?

I have a bunch of computers (over 10) that just sit at the house. I have and extra 24 port switch and want to practice at the house with setting up an full business office from scratch. I have MSDN and want to know what to setup and in what order is the recomended order. I want know I want DNS and DHCP setup including an mail/exchange server, SQL server, print server, web server ect. What would you recomend that I add and which order? Thanks for any info.