You will need a full desktop computer (a laptop could be used) to act as the server already running Debian Linux. If you have a spare computer that you do not mind losing what is on the hard drive, you could install linux on it and go from there. You need a computer network to connect the thin clients and the server (usually a network switch and cabling). You need some thin clients that support the rdp protocol. Not all thin clients do. I have some thin clients that expect to load the software to run them selves from the server when you turn them on. So if you plan to purchase thin clients you need to know these things. You will want some that have the needed software already built in. Purchasing used thin clients from the net can be a real minefield of problems. I know I bought some units of one kind and ended up with 4 good ones out of the six I bought. Sellers tend to sell them with parts missing. But I bought them so cheap I can not complain. The Compaq Evo series is what we use most. We also use some Neoware units. Both companies were bought by HP.. The Wyse unit pictured is based on the Compaq EVO series.
Note: if you have an Android or Ipad tablets with an rdp application, skip over to step3.
Linux oesrvr104 2.6.32-32-generic #62-Ubuntu SMP Wed Apr 20 21:54:21 UTC 2011 i686 GNU/Linux
$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 10.04.2 LTS
Release: 10.04
Codename: lucid
$ sudo apt-cache search xrdp
xrdp - Remote Desktop Protocol (RDP) server
What about a window looking out over a grand waterfall, or an erupting volcano. Or how about a live feed from times square? Perhaps a view of the Eiffel tower! Or maybe just the puppy section of a pet store. Or the chimpanzees at the zoo.
You may need to modify the file /etc/sudoers using admin rights. Lots of security issues modifying that file though.
1) Install the packages for ltsp and build the thin client environment.
2) Configure the network interfaces by easily editing one file.
3) Configure the DHCP server by easily editing it's configuration file.
LTSP also doesn't require to use special login software on the thin client, just the PXE network boot which is part of the BIOS. This also makes it very easy to set up new thin clients as you just need to plug them in.
I appreciate your comment, but I can have my network up and running before you finish your first step. If you really want easy ltsp, may I suggest the live ltsp dvd. Ltsp is about to get replaced anyway. I forget what the new version that Redhat is working on will be called. It is supposed to be awesome.