I've had to rehab a shoulder (among many other injuries) and here's what I've learned:
1. Strength first, endurance later
2. Rubberbands/soup cans for rotator cuff
3. Ice therapy
4. Patience
Concerning 1: If you can only do body weight excercises, be sure not to excercise to failure in a given set.
The uninjured muscles will be strong enough to allow overtraining of the injured ones.
Limit your range of motion. Partial pushups will help keep the shoulder stable.
Concerning 2: There are cheap "rubber band" excercise tools you can get at most sporting good stores (they resemble surgical tubing with handles).
Soup cans are about the right weight to use for rotator cuff rehab.
Excercises can be done with either the rubber band or light weights (soup cans).
Rotator cuff exercises:
http://www.bodyresults.com/E2RotatorCuff.asp
A few words of warning:
-
MORE WEIGHT DOES NOT GET BETTER RESULTS, a soup can or 3 lb dumbell is sufficient.
-Do the rotator cuff excercises at the end of the day, when you intend on doing no more excercises.
-NEVER DO THE ROTATOR CUFF EXCERCISES IMMEDIATELY PRIOR TO A WORKOUT.
Concerning 3: Ice your shoulder for 12-15 minutes, every hour or two.
A bag of frozen peas works great for this.
Be sure to get you muscle temperature up (warmup) before excercise.
Concerning 4:
It will take as long as it takes.
Working it "harder" than necessary will not speed up your rehab, it will set you back.
Good luck.