Do you have a Windows Server 2003 or above versions?
Please have a read on the requirements here
Q's and A's:
1. Is a WSUS server what I need or is there a better solution for updating multiple computers with fresh installs?
How many Client computers do you have? If you have 20 or more you may use WSUS.
2. Do you have a good resource for setting up a WSUS server, like a youtube video or website with step by step instructions.
For Windows 2003 Server: Step 2: Install WSUS on Your Server
For Windows 2008 Server: How to install WSUS on Windows Server 2008
3. Hardware, will any tower work for this or should I get say an older dell 2950 to do this? The faster I get these updated, the faster I get paid.
I'd say at Min of 1gb to 2gb or RAM. Plenty of HDD space bec. the logs do get pretty big.
4. Do I need separate servers for each OS (XP, Vista, 7) or can one server do it all?
One Server would do it all.