When we look in the mirror at times we usually see the front like the arms, shoulders, head, neck and torso but we don't always see the back. When you have a powerful looking back it helps make the rest of the upper body look good. Now do we really need to do that for looks? No.
Building muscle in the back is a key component to having great strength and power. The columns all over the back with strong spinal erectors and the latissimus dorsi that makes the upper portion of the back powerful and strong. With pull-ups you can create the ultimate workout with that part of the body but its bot just building the back, its building the upper arms, forearms, your grip and believe it or not the shoulders and abdominals.
Strengthening the tendons goes a long way with pull-ups. Look at the apes in the jungle and how muscular they're backs are for their size. Do they do pull-ups for reps? Hell no but they climb and use every part of the body to make that climb. We can adapt to that by doing pull-ups. Now at first doing them is a bit of stretch especially for a big person (take it from me i'm 240+). So with that in mind we must work on tendon strength not so much muscular strength. Building muscles won't always be enough but when you build up your tendons thats where the real strength comes in.
Most people look at pull-ups at 2 different variations (palms facing away and palms facing towards you) but there are many variations and hand positions. This is where being mindful and learning from different angles creates your own training and being your own personal trainer.
At first doing pull-ups may be out of your reach so start with hanging onto the bar. Learn to hold on and build that grip strength. Move up a bit inch by inch in isometric fashions. Keep that consistant and before you know it you're doing pull-ups. I know this and am an expert on that because i've been there and its not easy especially for a guy my size. With that in mind if you want to become a pull-up master you have to learn from the best. In my opinion its Garin Bader & Cees De Kok. These two strength powerhouses are some of the best at what they do and it not only keeps them healthy but injury-free and they want to show you through Pull-up Workout Strength Training. I have met both these men and trained with one of them personally and I can honestly say they know what they're talking about.