IMO one of the biggest differences between LHE and NLHE is that the odds
for draws are almost always there in LHE. In NL you can bet out draws, as well as be bet out of your draws. In LHE your pocket pairs are alot less valuable than in NL, as you can't bet out the draws.. especially at lower limits. I can't count the amount of times I "jammed the pot" (or raised/reraised at every opportunity) with QQ/KK/AA only to be drawn out by a straigh or a flush... when i started playing LHE. I play them a lot smarter now.. yes i will raise/reraise preflop, and bet the flop if there isn't 3 to the flush or 3 to the straight. I always take count of the draws that are possible and if a card comes up that makes the draw.. i'm out.
Limit is a lot less frustrating at higher limits. But even at lower limits i do alright by mostly playing drawing hands.. any ace suited, suited-connectors.. these types of hands. Of course I'll get in with premium hands but, i play them alot more cautiously than I would in NL because i'm probably up against multiple draws.
As for whether to play Limit or NL starting off... I've built my smaller BRs by playing the .01/.02 NL games on Titan, and the cheap SnGs, adhereing to the 5% rule. You can build up your BR a lot quicker with NL. You can play Limit, but it's probably going to take you a lot longer to build your BR.