The above link is for the simplest type of connection. What I would call a Link & Favourite. You link once and then use the Favourites to remember the link and the keychain to store the login details. While simple .. it involves opening the Connect to Server dialog EVERY time you restart the Mac not as convenient as a Mapped Drive.
I am assuming you are running OSX 10.5 Leopard (not earlier versions of OSX) and that you are not trying to join the Macs completely to a Windows Domain Server (this can be done but there are a few other things to do). You just want to mount a network share and be able to get to it each time you restart.
You should read this article from Microsoft about how to fully authenticate against AD and how to configure everything.
http://download.microsoft.com/download/5/3/c/53c9bd6b-6927-43ca-8871-f3b60db13968/SBSMacDoc.docFor a list and overview of all the different ways of connecting Macs to Windows PCs .. see my posting in this previous discussion, if you're running 10.5 then look at the Applescript option (4)
http://www.experts-exchange.com/Apple/Networking/Q_22427567.html
