need a book about nutrition and advice on what to eat.

well my girlfriend and i have been working out the last few weeks and she goes to a place called curves in the area and she is doing pretty well and i have just been running. i was in the army for 3 years and got out in october so i can still run pretty good. i can run about 4 miles w/o stopping and i can run 2 miles in about 16:30 (i know thats not really fast i use to do a lot better) well when i got back from iraq i weigh about 175 lbs. im 6ft when i got out of the army i was at about 190 and now that i sell cars for a living 10hrs a day with no phicial work i weigh about 250 lbs. i need to start running and lose this weigh. when i was in the army all we did we eat steaks and pizza and drink beer but i was so active i could burn everything off. anyways i have no idea about cal counting and what food is good and bad (other then the obvious ones) my girlfriend doesn't know anything about eating healthy either so basically im just looking for some tips and even a book that explaned the different stuff in foods and what is good and what isn't would be great.
thanks,
joe