Bulking is overeating on purpose. Sure, it sounds fun but only because you've never had to force feed yourself chicken.
The purpose of bulking is putting on weight. You want to add more muscle and you want to add more energy reserves. The energy reserves are important because if there isn't enough fuel for the body, it'll just start stealing from your muscles. During a bulk, you should not be losing muscle mass.
Due to this, your carb and protein percentages remain about even while fats take up the remainder. A 40% carb, 20% fat, 40% protein split is a decent ratio for a bulk.
To grow muscle, plan to eat 1.5g of protein per day per pound of weight on your body. For example, if you weigh 150 pounds, you'll want to eat 225g of protein each day.
Cutting is eating less on purpose. Though you might thank your lucky stars you don't have to force down any more food, the initial hunger pains can be a real bitch.
The purpose of cutting is to lose weight but not just any weight. The trick here is to retain your muscle mass but drop your body fat percentage. Interestingly enough, the key to this is not cutting fats. In fact, you have to increase your fat intake. Instead, it's all about cutting carbs.
Carbs are the body's first source of energy. If you have a surplus, your body won't touch fat storage. Severely restrict these, however, and the body is forced to rely on its fat. During such low-carb phases, the body produces ketones. This is why low-carb diets are often referred to as ketogenic. This typically happens when you eat only 20-50g of carbs per day.
A good cut split is typically 20% carb, 35% fat and 45% protein though this can vary based on the restrictions you've placed on your carb intake.
During this phase, you should stop focusing on increasing muscle mass and instead work to maintain. To do this, eat 1g of protein per pound of your weight. For examples, if you weigh 150 pounds, plan to eat 150g of protein each day.
From what I've researched so far, your cut should start 8 weeks prior to the date of the event you want to show off for. That being said, the only way you'll know for certain how much time your body needs is to try it out yourself.
Most lifters and builders have an on and off season. They'll cut before a show or competition and then go back to their bulking phase. Depending on how often you put yourself on display, you could end up spending half the year doing one and half doing the other. Just remember that like everything else, too much of one aspect can be bad. Find your balance.
Co-host of HeroesForge, founder of Battle to Be Better, gamer, singer and all around happy person.