A little bit of research can go a long way, and I suggest Livestrong.com, theres a ton of free information and people there that may help you.
But my advice to you is keep working out, 3-4 times a week, more if you feel so inclined, and be sure it's a mix of cardio and weight lifting.
For every pound of muscle you gain you burn something like 35 extra calories a day; but you don't even have to go that far. Just lifting weights enough to raise your heart rate and break a sweat is enough to increase your metabolism and keep it up for longer after you've finished your work out.
But don't forget your cardio, that's also key. Cardio exercises will burn more calories faster than weight lifting, it just wont have the same metabolism affect, though not to imply that it doesn't increase your metabolism any. I'd say something like a half hour of both, or whatever you can handle, each workout.
As for your diet, try eating healthy small meals or snacks that are low in calories every two to four hours to keep your metabolism up and burning more calories. After four or so hours your metabolic rate drops and the next time you eat more calories are stored to be burned later on, (fat). Just be sure you're still getting everything your body needs in a day, and be sure to talk to your doctor about whatever diet you think up. If you're not smart about this the weight will just come right back, I promise you that.
One more thing, don't mistake thirst for hunger as many people do. Know when you're actually hungry, drink lots of water, and try and understand what your body is craving. Whether its protein or carbs etc. (And 16oz of water when you wake in the morning has been proven to help raise your metabolism for a significant amount of time)
I hope this helps, and good luck:)