I'm what I guess you might call an accidental sys admin. I don't have the training, and the guy who used to do this left last month, so I'm it.
Before he left, he requisitioned a new Windows Web Server 2008 R2, which just arrived today. So, I've got to put it into the rack and get it joined to our domain. We're using a Windows 2003 R2 Active Directory. Naturally, I want this join this new server to our domain as a member server, but I've never set up a server before, so what steps do I have to do, to get this up and running?
Please refer to this EXCELLENT Microsoft TechNet Article about joining a new machine to a domain. It's quite easy. I'd also like to reiterate that the new server's DNS settings should be pointed to the Domain Controller.
PS - The second link says Windows 7; ignore that. Just follow the directions if you need them.
Follow the same steps as a Windows 2003 server. You don't have to do anything different if the member server is a version ahead of your domain controllers. Just go to System Properties, and join it to the domain. As with all things of this type, make sure it's using the DC(s) as its only DNS servers.
/edit - and if this gets your palms sweaty, then you need to be prepared to learn on-the-job very quickly, and might be wise to get a list of immediate things you need help with and can hire a consultant to 1) Do and 2) teach you what they're doing as they go.
Join the server to your domain just like you would any client computer running XP or 7. There's nothing special you have to do, just because it's a server.
The trick would come in if you wanted it to also be a domain controller (and even then, it's not that hard). Not all servers on the network are domain controllers.
About the only things you'll need to do different for this server are give it a static IP address and make sure to install Web server role from the server management screen that should open up when you log in. You may also want to turn on the .Net 3.5 feature, if it's to run an asp.net web site.