Markets change. Buyers are most often easier to access and work, but not so much right now. Normally, I would say start as a buyers agent, since it is easier to get started than it is becoming a list agent. However, right now listings are easier to get since our market is more listing heavy. I am pretty familiar with your area. It might be wise to explore BOTH ideas. Most often getting listings is a much greater challenge than it is right now. If you apply your self to FSBOs, expired, and or short sales...you might find great satisfaction in helping first time home owners sell and become move up buyers. Just a thought.
And once you get a listing or 2, then the buyers call you as VT so profound wrote earlier. So be ready to get busy.
But try and come rounded as an agent. Niches are great-do not get me wrong. If you are around alot of young people in your life you have a great oppotunity to help them buy homes for the first time. Just don't limit yourself...sky is the limit Priest.

As the saying goes, "List to last": I am of the conviction that getting listings is the way to go IF POSSIBLE. OF course, you have to be pragmatic and take what business you can get when first starting out. But if I were just starting out I'd dedicate a certain number of hours each week to trying to get listings and networking for those types of contacts and referral sources.