As someone who is in the gym everyday and understands nutrition I will tell you that a solid ratio of protein, complex carbs and non-saturated fat is extremely important to maintaining muscle mass and losing fat. I'd recommend a 40/40/20 (p/cc/f) ratio while building muscle 50/35/15
so long as your not morbidly obese, now is not the time to diet. Enjoy the rest of you summer and consume. After Labor day limit yourself to 10-12 alcoholic drinks a week and stay away from sugar, anything white (pasta, bread), and fryed food. Instead eat as much chicken, tuna and wheat (anything pasta, bread, bagels) as possible. Calculate how many calories it takes to maintain your weight and eat more (
http://www.freedieting.com/tools/calorie_calculator.htm#) Understand something,
it's impossible to gain muscle without gaining weight and impossible to gain muscle while dieting. Now, obviously go to the gym while doing this 4 to 5 times a week. Hit Legs (quads, calfs and hamstings) on day 1 and follow that with the muscle you most want to grow. For me it's
Day 1 - Legs
Day 2 - Arms
Day 3 - Shoulders(abs too)
Day 4 - Chest (abs too)
Day 5 - Back (abs too)
Also, for every drink you are planning to consume on the weekend jog/run to burn off 100 calories. so 10 drinks = 1000 cal.
Day 1 - Legs
Day 2 - Arms
Day 3 - Shoulders(abs too) 333 cal. run
Day 4 - Chest (abs too) 333 cal. run
Day 5 - Back (abs too) 334 cal. run
Drink more = run more but try not to go over 12 a week (drinking is draining)
Let loose and have fun with friends on new years and then be prepared to stop drinking and diet come January 2nd and until memorial day (22 weeks or longer if you want). Again weigh in (hopefully you weigh more) and calculate your maintenance (
http://www.freedieting.com/tools/calorie_calculator.htm#). But this time eat less (knowing 3500 calories = 1 pound.) if your maintenance is 3000 calories a day and you eat 2500, that's 500 x 7 days in a week = 3500) meaning you lose 1 pound every week. don't lose more than 1.5 - 2.0 pounds a week or your losing muscle.
Diet to lose fat not muscle.