Wednesday's poker guide discusses the dynamics and difference involved in playing heads-up poker.
"Do you like to play a lot of hands? Do you like to read players? Do you like to play the player more than the cards? Do you like to bluff? If you do then heads up poker is the penultimate form of poker. You are sitting down against only one opponent. As both of your holdings are likely to be weak, you are playing most of your hands while relying on aggression and strategic moves to defeat your single opponent."
The article can be found in the beginner guides sub section of poker guides area of the poker section in the sub tabs.