I agree with topgun. Check it out real good and set it up for you.
I bought an '04 150 for my son new. All we ever did to it was replace the air filter with a twin air, pull the snorkle from the airbox, remove the baffle at the end of the exhaust can, and rejet the bike (if you decide to pull the snorkle and baffle...be SURE to rejet or you may burn the engine up.) I am a big fan of Seal Savers (
www.sealsavers.com ) so we put a pair of those on. That was it. In all, it was about $75 worth of mods (pretty cheap.) The rejetting, snorkle and baffle removal will give extra snap to the bike when you're ready for it.
The bike ran like a top. He has since graduated to the 230. dk54red wrote a little something about the suspension and I agree. The suspension on the 150 is soft. The 150 (without significant mods) is NOT a track bike. It is meant for the woods and fun rides. As a noob, this bike should be great for you.
Hope it works out. BTW, we are in Omaha and ride pretty regularly at River Valley OHV park. If you're ever looking to come riding up there, send me a PM and maybe we can meet up for some riding. River Valley is pretty tame, but it has some really good trails for a noob to get some experience with.
Good luck and welcome!