You can observe your wear pattern on your tires that will tell you a lot of history on the behaviors of your vehicle. You should have your alignment checked approx. every 30k miles. The pulling may be caused by a faulty tie rod.
There are a few things that could cause your car to pull when braking.
I would first check your tire pressures to make sure they are okay. While you are looking at the tires see if they are worn unevenly at all - that can be a sign that you need an alignment.
However, it could be a sticky caliper or a worn suspension component such as control arm bushings. Before throwing money at the problem, I recommend you have a ASE certified technician take a look at it and see what she/he thinks.
〉 Answered on May 25th, 2009 by Bogi Lateiner, Owner and Technician at 180 Degrees Automotive