Also, when you decide to move on to a more advanced method, you should know that there are multiple methods which have the potential to become extremely fast. The Fridrich method is the most popular one, and is what you hear about a lot- its steps involve making a cross (which you most likely are familiar with), then solving the first two layers (most often abbreviated as F2L) simultaneously, and finishing with OLL and PLL. OLL stands for Orientation of the Last Layer, which in case you don't know is simply making all of the LL cubies face the right way. PLL stands for Permutation of the Last Layer, and moves the cubies around so that the cube is solved.
This is definitely not the only way to solve the cube quickly, though. Other methods you should definitely look into are Roux, Petrus, and ZZ. They all have their own wiki pages, and there are a few written tutorials as well as video tutorials floating around which are all really helpful.
Fridrich:
http://www.youtube.com/user/badmephisto
Roux:
http://www.speedsolving.com/forum/showthread.php?t=11506
Petrus:
http://lar5.com/cube/
ZZ:
http://cube.crider.co.uk/
I definitely think you shouldn't wait too long to switch to an advanced method, but at 3:00 you should wait a bit. When you get to a 2:00, 1:30 average, look into these sites, or others that you find, and decide which method is best for you. Good luck!