Here's some advice:
--Consult the Consumer Reports Buying Guide that they put out every year(you should be able to find these in a good library). They do full reports on ALL cars, including reliability, performace, comfort, etc etc. They give advice on good cars to buy as well as what cars to avoid.
Based on my own experiences, from reading these guides, as well as knowing friends with new(er) cars, here's my advice:
--Great cars: Toyota, Volkswagen, Subaru are all VERY good cars. I drive an older Subaru that runs great, gets really good milage, is very comfortable, and has needed few repairs. I've heard newer Subarus are even better! VW's are also very reliable cars(though some of the New Beetles have had problems), especially Golfs or Jettas.
--AVOID THESE CARS: Ford Mustang; one of my SAI sisters owned a 2001 Mustang and it was a piece of crap...it broke down on her constantly, didn't get good milage, and just all around was a lemon. Chevy Caveliers(some years) have had a lot of problems, as well as some Fords.
Hope this helps at least a little. Good luck, and keep us posted!