I've actually done this before! Here are a couple basic steps, assuming you're working with a similar environment:
- Set up Server 2008 on your IBM machine.
I'm assuming you have a router of some kind in your home, and that you can log in to configure it.
- Make note of your router's IP address, specifically whether it's 192.168.0.x or 192.168.1.x (emphasis on the 0 or 1--different routers will use one or the other by default)
- Give your server a static IP address inside the same subnet as your router.
- Install the AD DS role, as well as DNS and DHCP roles.
- Set up your DHCP to use the same scope as your router--192.168.0 or 192.168.1--and use a mask of 255.255.255.0
- Configure your DHCP scope options to specify your router's address as the gateway (003 Router) and add your server's static IP to the dns list (006 DNS Servers).
- DISABLE YOUR ROUTER'S DHCP! oops, hah. forgot to write down this step.
This should allow you to leave your W7 machines on DHCP, while still making them aware of your server as the primary DNS and knowing to get to the internet through your router.
- Pick the domain name for your home network, and finish the DNS configuration.
- Add domain users on the server
- On your W7 machines, either reboot or run "ipconfig /renew" from a command prompt
- Click Start, and right click on Computer. Select "Change Settings" on the right, and then enter the domain you configured.
- If you get an error stating that the domain could not be contacted, attempt to disable/enable your network adapter in the network and sharing center--this seems to work fairly frequently.
- Go nuts!
Hope this helps. Additionally, I'll agree that wikipedia is a valuable resource as a launchpad for learning about various topics. IT is a ridiculously huge bowl of alphabet soup, and even a brief primer a la wiki pages can get you pointed in the right direction.