To connect a Linux box as a desktop is not all that difficult, but can take some time and experimentation. I have a Linux desktop on a total NT domain and have been running it for more than a 1-1/2 years starting with version 6.0 (RH). I am now running RH 7.1 Fisher.
1. Once you have your box networked you will need to have Samba installed and configured in the OS. Your main Samba applications are smbclient, smbmount, and smbumount. I used the smbclient to see the resources that were availableto the server that I was connecting to. Smbmount will mount the resource (map a drive) to your box and smbumount will gracefully unmoun the resource. TechRublic has a lot of documentation on the set up of Samba and the How-to will give you a lot of insight to its configuration.
2. You did not mention printing. You may want to have your printers setup to use tcp/ip. I have found that this works well for me.
3. Netscape mail can be configured for Exchange mail. You will need to have the ip address of you mail server to connect. Also there is StarOffice, it will connect to exchange.
All of what I have mentioned is available on TechRepublic in drill downs. I have been use their resources since 1999 and have found them to be extemely useful.