General question re server sizing

[finfan365]

I am currently in college, and assigned a project of designing an IT infrastructure for a small college with 3 campuses. I've never looked at enterprise level servers before and get a little lost when I start reading each spec sheets.

One thing I've looked at is the C3000, but I'm not too sure what I need to have in there. It needs to handle 1000 to 1200 concurrent users running windows XP, in an Active Directory environment. I also need http, dns, dhcp,and ftp. When do I need to start adding processors/memory.
I know I'm asking a lot, but even if someone could give me a good starting point I would greatly appreciate it.
THanks

[JKytsi]

Hi,

Here You can find ready made solution blocks with blades. Ready to order and certified =)

http://h18004.www1.hp.com/products/blades/solutions/solution-blocks.html