good first car for a first time driver?
if that is the case...NO. its rather large and the visibility out of the rear windshield is poor. its safe, for you (the driver). its will be hard to park on the street (if you live in the city). a better first car for a first time driver would be a Civic (low end/ budget) or a BMW 3 Series (high end).
now if this is going to be the first car you purchase for yourself and have had several years driving experience, preferably drivng trucks and SUVs, then do it. the hummer H3 is more of a soccer mom car, but it will hold value pretty well (i imagine) the H1 and H2 seem to holding their value pretty well. the car is definitely safe and GM reliability is hit or miss.