I like Pavel's GTG, like was mentioned above. Many programs will work but bottom line is be consistent and have a plan. Do negatives and dead hangs for time until you can do at least one rep.
Now that you can do one repetition it is time to Grease The Groove.
There are a couple ways you can do this. The first way is to do one rep,
rest 30-90 seconds and perform another. Continue until you are pretty sureyou can't do another one. Repeat the every day or every other day.
The second method is to do a rep between every set of your regular workout.
For example, if you are doing a bodyweight Strength Circuit it would look like this:
Push-ups x20, Pull-ups x1, sit-ups x20, Pull-ups x1, Lunges x20, Pull-ups x1,
and so on and so forth for the entire workout.
The third method is to use the timed method. Set the timer on your watch for
15, 30, 45, or 60 minutes. When it goes off, do a rep. Continue all day.
Any of these methods will render results in short order. Test your self each week.
When you can do five or more its time to shift gears.
Now we can begin to get serious about big numbers. Here are a couple of proven methods.
First we have The Spetsnaz Ladder method. With a partner or simulated partner (you figure it out),
do one rep, and then your partner does one. You do two, he does two and so it continues.
When one of you is close to failure, stop and start over.
It will look like this: 1, 2, 3, 4, 5 -Rest- 1, 2, 3, 4, 5, etc? This is far more effective
that the Pyramid method which looks like this: 1, 2, 3, 4, 5, 5, 4, 3, 2, 1.
Method two is the weighted method. Add 5-10 lbs to your body and do any of the methods
listed above. Alternate workouts so one day is weighted, the next is bodyweight only.
Do not exceed 15 lbs added if you are looking for numbers.