Small Potatoes

I need some basic guidance in setting up a 20 node shop with internet connectivity through DSL and an Exchange server. I need a somewhat comprehensive resource to assist with this task. Are there any that you can think of that might have the stepsto setting this up? I am not a neophite technician, though most of my technical life has been in project management on the tech side guiding other technicians to do the hands-on stuff. I am now part of a start-up and as such have been tasked with setting up the network as funding is tight right now. Please dont be too critical… I really need some help. Thank you in advance.