The best place to get some info is on the Microsoft site, as it is part of windows 2000 server. The reason we run an 800 desktop network with it is:
1. Install applications once in a central location, not needing to visit each desktop.
2. Support is far easier. If a desktop fails we spend 30 mins trying to fix it. If we cant we through it out and install a thin client box instead. If the user calls in with an application problem i.e. how can they change the margins in their word processor, you can shadow the user and show them how to do it instead of trying to talk them through it over the phone.
3. Network traffic is reduced as only key presses and video displays are sent across the network. That is why it works so well with remote dial in i.e. RAS.
4. Security is far better as no information is held on the computers local drive except the connection software that takes up only a few Megs of space.
5. It brings control back into the hands of an IT department.
6. It will allow you to run a program such as office 2000 on a 386 computer. And if you were to compare the time it takes to load a program via terminal server and a local installed application. The terminal server application will be load far quicker than the local installed version.
7. If you have a large database and you wont to run a query on it that takes a few hours. You can run the query and then disconnect go home and leave it to run over night. When you come back in the morning you can reconnect and you will pick up from where you left off but the query will be finished. This is because the processes you start as a user are not be killed when you disconnect' a bit like switching of your screen on your home computer and not the base unit.
Disadvantages are few and far between but you do need to know.
1. As the information is stored on remote servers, if those server go down your users will stop working. This is also true for the network be it Ethernet, ISDN or PSTN.
2. Upfront cost. Although it is slightly more expensive to implement at the start, you very quickly save money with technical support and software deployment. It also means your company can keep there desktops until the desktop hardware fails before needing to replace them.
We use a product called Citrix XP installed on top of windows 2000 to provide some more features but this is not necessary.
I'm sorry if I went on a bit but as you may be able to tell I love it. It's the best thing since the days of main frames; in fact the principle is very similar to that of about 30/40 years ago and the use of main frames.
You can get more info from Microsoft.com and citrix.com. Also have a look at thinplannet.com.
Should you wont to know more give me a shout.