As others have already mentioned, whether your want to bulk up, or lean out (I do both throughout the year), diet really is key.
Everyone has their own way of doing things, but I can share what I do.
Right off the bat, protein is essential. Whether you want to put on muscle during a bulk up, or make sure you're preserving muscle while cutting, you want to make sure you're getting in adequate protein. Based on what you said you're current weight is, (in accordance with the 1 gram per pound method), you should making sure you're getting at least 110-120 grams of protein per day. If you're protein's not at the right level, all the hard work in the gym could be for naught as you'll see very little progress.
In terms of controlling your mass, carbs are a huge factor. In the wintertime when the primary focus is putting on muscle, my carb intake gets higher...in the spring months when I'm cutting up for pool/beach season, my carb intake gets much lower.
Ideally, you want to be hitting your numbers with real food. Far too often people try to rely on protein shakes or "mass builder" shakes... It's okay to supplement your regular food with a protein shake here or there...or if it's a day when you were really really busy and didn't have time, replace a meal with a protein shake. However, the ideal scenario is always real food.
I've been at both ends of the spectrum. Some years back, I was around 230lbs (overweight)...not the good kind of 230...the kind of 230 with a 38 inch waist lol. I did a variation of the carb cycling/paleo diet, and dropped to 160lbs (I'm 6'1" as a point of reference).
Over the last 2-3 years, the focus has been putting on muscle (while staying lean). I've put about 20-25 pounds of lean mass on during that time frame. This last winter during "bulk up" season, I was about 190-192...right now (just finished up spring cut) I'm at around 180-182.
Here's a sample of what my diet looks like during each part of the process.
Bulk up season: (5 meals a day)
Meal 1: 4 egg whites, 2 whole eggs, oatmeal
Meal 2: Chicken & Rice
Meal 3: Pork & Potatoes
Meal 4: More chicken & rice
Meal 5: Steak, Broccoli, and potatoes (small serving of fruit for dessert)
(Total caloric intake around 3200-3500)
Cut up season: (4 meals a day)
Meal 1: Eggs & Bacon
Meal 2: Chicken & Broccoli
Meal 3: Bison & Carrots (one of my favs)
Meal 4: Steak, green beans, and a small serving of fruit for dessert
(Total caloric intake around 2000-2200)
In both instances, I'll occasionally toss in a protein shake throughout the day.
(usually on days when I'm hitting a larger muscle group)
This is just a sample, I switch up the meats and the veggies typically...and I'll toss in a 2-3 cheat days per month. (to keep my sanity)
...and obviously, you have to put your time in, in the gym. (I typically try to hit each muscle group 2-3 times per week)
The biggest mistake you can make going into it, is expecting fast results. People see pictures of guys like Mike O'hearn and think "with a couple of years of hard work and eating right, that where I should be"...that's a sure fire way to set yourself up for disappointment. Guys like him are the product of not 2-3 years of hard work...they're the product of 15-20 years of hard work.
For reference, this is Mike O'hearn (at age 44):
Part of the problem is that the (largely unregulated) supplement industry is filling people heads full of nonsense making them think that "if you just take this supplement and work out, you'll look like this in a year"...yeah, not so much lol.