Hi Cathefan,
You will receive lots of different advice here and the bottom line is that no plan is perfect for everyone so you may have to experiment a bit to find what works for you. Some general rules, though, are to eat "clean" (i.e. as close to nature as possible, no highly processed food or simple sugar/empty calories), to fuel your body on small meals every 3-4 hrs., and to drink enough water that your urine runs clear when you go to the bathroom.
A good book that I read this spring is "Power Eating" by Susan Kleiner. She's a registered dietician who works specifically with athletes, both recreational and professional, and addresses specific nutritional needs of people who train seriously. She also guides you in setting appropriate goals in terms of ideal body weight and body composition.
FitnessRN