I have searched countless phrases to find an answer and can't quite figure this one out. It is to my understanding that (as it was many moons ago at universities and the like) you can still use one central setup to do the processing/video/account/file management and have terminals to access it that merely function as a screen, keyboard, and mouse which to provide input back to the main PC.

SSH is an easy way to do this from a command line point of view, but I have a few old laptops that would function excellent as terminals, while leaving the load to my self-proclaimed super computer... Ex: My significant other has an old Dell mini 10... The thing is total garbage, even for surfing the web, EVEN AFTER a factory reset... but it does have a decent processor and a Gig of RAM. I was thinking to do a minimal ubuntu install and then lxde or e17 or the like for a DE... but what might be better is to keep it a command line variant that can let the desktop take the burden and just use it as a terminal...

This would benefit me more, I think, because it would allow the laptops to run smoothly (I have a few of them I'd like to revive through this cause) but more so I can manage all user accounts, homes directories, and installed applications right from one system...

I am by no means a Linux pro, but even if no one has time to tell me step by step, even a push in the right direction with which programs to use would mean a lot to me. I'm guessing this goes a step beyond SSH and involves so kind of setup with an X server, but again, I'm guessing =)

Here's what I'm looking for summarized:
I would like to, from any ubuntu device, have it set up so that when booted, it will connect to the desktop. Then they can proceed to use the laptop as a terminal and connect to the desktop as if they were sitting in front of the screen/keyboard/mouse attached to it.

Thanks in advance for any help!