Limit is a great starting game for a few reasons. First, like XD stated, the mathematical portion of the game is much higher and limit requires much more on-the-fly analytical thinking than NL in a lot of situations. The other big reason to start with limit games is that you will, to a large degree, mitigate your losses in the learning stages of your poker career. Rather than either having all-in fever, or being run over by someone who realizes you're new and that you don't want to make a decision for all your chips, you will learn how to properly bet cards for their value and not rely on a card catching contest to win you your first online pots.