Hi all,
Since posting, I've found a very handy guide + circuit diagram detailing pretty much what I want to do.
Here it is: http://www.electronic-circuits-diagrams.com/remotecontrolsimages/remotecontrolsckt5.shtml
Problem is, you can only have up to 12 devices as (I assume) that's the number...
I'm new to the forums so I'll say hi first :) - have been reading the rest of this section and it seems like a great place for a novice to learn! I've had a very small amount of experience with electronics, but have worked on software (Basic, PHP if anybody's familiar with those...)
Onto my...