tips for learning tells ....

So,

I'm finally getting a little more comfortable with my home game and somewhat have an idea of what people might have now. I really think it's more of a subconscious thing though, and I'd like to learn some good ways to start picking up on them.

So, let me ask these questions:
(a) which tells do you find are the best indicators?
(b) how do you suggest I watch for them, and at what times

On my own note, here's what I've noticed so far:
- try to focus on one person at a time rather than the whole table
- always beware of someone that has been quiet and is suddenly talkative (or anxious to get the game "moving" when someone isn't paying attention)

send tips!