I'm 16, 6'2", 265 pounds. It isn't muscle. Long story short, I got sick of being fat and had a free membership at the YMCA though my school, so I've decided to start a serious workout program. For the past two months or so, I've been working out 3 times a week for an hour on an elliptical, but after not noticing any results and doing a little more research, I think I'm going to step it up a little bit. I'm working on cutting my caloric intake gradually down to a 2000 calorie/day diet without a ton of carbs or fats and with more fruits and veggies. What would you guys advise for my workout routine? I'm pretty new to working out, I think some advice would do me some good. My goal is to lose 3-5 pounds a month until I get down to 200 pounds, then reevaluate from there as to my next goal.

I would also like to build a bit of muscle in the process, I don't know how doable that is.

Try a heavy lifting muscle for 30 minutes a day. You still need to eat some carbs in order to burn carbs. Have enough sleep and drink more water too.