Lats
Lats (Latissimus Dorsi) include the muscles, Teres major and Teres minor. They're a very important part of a person's physique, adding width to the body and give it that “V” look. It's a very big muscle and it can handle a lot of weight and resistance training. Lats tie in with all the other muscles in the back, especially the rhomboids which are in the middle of the back. Therefore, a lot of exercises that primarily hit the lats, will work either the traps or the rhomboids as well. There are a wide variety of exercises you can do for your “wings” but try not to do more than four, three should be enough. A lot of exercises for the back can be done on machines because it is not a particularly easy muscle to reach without them.
In order for the most effective results, you need to make sure that you can recover effectively after your workouts. You can do this by using a supplement such as Natural Stacks Whey Protein/Collagen, because using that protein powder should increase your ability to recover over time.
Here are the best exercises to target and build your lats.
Pull Ups
These are most definitely the best possible exercise for your lats if done properly.
First, always use the widest overhand grip possible that will not restrict your range of motion. If you do pull ups reaching the bar behind your neck, then you will involve your traps as well. That's why we prefer this version of pull ups to the one where the bar is in front of your face. When you do front pull ups, the bar should touch the top of your chest and you should go all the way down, into the darkness. Then pull yourself all the way up, reaching to save your life.
If you do it the other way, make sure the bar touches the top of your traps or at least the bottom of your neck. Never swing or jerk your legs, that will just take the emphasis of your lats. However, if you don't have a spotter, you might have to resort to cheating to complete the last few reps to squeeze out just a little bit more intensity (don't make a habit of it though). Pull ups are best done first in your regular back routine.
They are a good warm up and finish up exercise. You can do these with weight after a sufficient warm up, but We don't recommend you add any weight until you can do at least 12 pull ups. Use a slow to moderate speed when doing these.
You can also use monkey grip to involve your lats (thumbs on top of the bar, not under).
Lat Pull Downs
If pull ups aren't the best exercise for lats then this is.
Most gyms are equipped with a lat pull down machine that will allow you to work with weight heavier than your own. It's a lot like pull ups, the only difference being you pull the weight to yourself as opposed to being pulled. The best way to do this exercise is using the same grip as pull ups.
However, you can also do pull downs with a close underhand grip, that will include your rhomboids more, but you will no longer grow your lats outward, they will just get thicker. Do 3 sets of close grips after doing 4 or 5 of wide grip.
This is one of the very few exercises that you do on a machine, free weights are always superior.
Seated Cable Rows
Works your lats in much the same way as close underhand grip lat pull down. To get as much of your lats involved as possible, pull the weight toward you stomach or even your crotch (basically just keep it low).
In this exercise, its easy to let your arms and shoulders do the work, but don't. Concentrate on your back, and make sure not to swing back and forth, that will work your lower back. Stay upright, you may tilt back slightly.
Bent Over Barbell Rows
Works not only your lats, but almost your entire back. Should be done with legs bent, about ¼ squat, back straight, almost arched and leaning forward a lot, almost parallel to the ground.
If you pull the bar into the middle of your stomach or lower you will develop the lower part of your lats.
If you pull the bar into the upper part of your stomach or close to your chest, you will train the upper part of your lats. That's the way to do them (upper), it adds much needed width to my back. You must go all the way down and feel the stretch. At the top, you should touch your body with the bar.
This is a basic compound movement and its one of the basics for building a strong muscular back.
Bent Over Dumbbell Rows
Most of the time, when an exercise can be done with either a barbell or a dumbbell it is listed here under one exercise and the differences are explained in the paragraph.
This exercise is so different from bent over barbell rows that it must be discussed separately. It isolates the lat very nicely from the rest of the muscles in your back. Your best bet is to do this exercise with one knee and one arm on the bench. The other leg is supporting your body against the ground and the same side arm is holding the dumbbell. Without swinging, at any pace, bring the dumbbell up and pull it in close to your body at shoulder/chest or chest/stomach level, slowly lower and repeat.
Make sure lats are doing the work, not shoulders and arms.
This exercise should not be done in the same work out as Barbell Rows. The two are interchangeable and should be switched from work out to work out.
Links for Reference
For more information, it would be worth considering reading this article from Muscle and Fitness Magazine.