by Jojon » Thu Dec 17, 2009 4:48 pm
Yes, you may want to begin with reading through the "Game Logic" section in the WIKI.
For pressure plates you'd use regions that triggers something(s) when the player enters (or leave) them, whereas switches/levers/pedals/etc would be "clickable objects" - from then on there are both much the same.
To make any complex-ish puzzles work, you'll need to use the Python scripting language, to resolve your conditionals; e.g. the typical "if all switches are on, then open the door" situation.