Start slow. Low weight or no weight so joints are OK throughout range of motion.
Pick simple routines for three to five muscle groups to start. Legs (stand up sit downs), chest (chest press, wall pushup), biceps (curl), triceps (press), shoulders (overhead press).
Focus on quality. If you are using the right weight and the correct form, you can get a better quality workout in a shorter time period.
Go slow. Especially on the down movement (should be at least three seconds).
Do one set of each routine.
Be fatigued in 10-15 repetitions. If you are not fatiguing, then the weight is too light.
Add weight slowly.
Keep posture nice and tall.
Use stuff around your house to start. Gallon of milk is 8 pounds. Use an empty jug and fill it with water to the weight you want. If you are sloshing the water during your repetitions, then you are doing them too fast.
Consume proper post exercise nutrition. Having something with both protein and carbohydrates helps your body repair and recover after a workout.
