I prefer to play NL. it's easier to trap, the pots are bigger and you can get more value out of monster hands. Off course it can also backfire, you can get trapped more, lose more money and lose value to a better monster . If you are new to online poker I think FL is a good option to get the feel of online poker, if your winnings are good you might want to chance to NL to increase your profits.
good luck anyway (I play for 4 months online poker, 1,5 year live poker)