[John Biggs]

Tells are far less important than you might think, especially if you are playing limit rather than no-limit.

Much more important for reading hands is figuring out what starting cards your opponents play, how they tend to play them, how they tend to play draws, how they play top pair, etc. From this you can then abstract whether they are loose, passive, aggressive, etc., which will help further.

Note that your technical understanding of the game must be at least as good as an opponent's before you can start reading him in this manner. Note also that you must be able to pinpoint how good/bad *his* technical understanding of the game is, so you can put yourself inside his head.

Worry about learning tells only after your use of the above approach has improved to where you're routinely putting weaker players on a range of possible hands based on their betting patterns alone.