From my own experience as a personal trainer, most overuse injuries of connective tissues from strength training are due to excessive reps and sets versus lifting too heavy a weight. You do need to choose a weight intensity that will tire the muscle group by the end of the repetition scheme in order to achieve gains in both strength and endurance. However, what you don't want to do is use weights that are so heavy that they enable a death-grip on the dumbbells or barbell, which will stress the connective tissues of the forearms and shoulders. So, keep this in mind when choosing your weight loads; if you feel you need a death grip hold to push or pull a weight, it is probably too heavy.
My advice would be: If you are going to use videos for weight lifting upon starting back (versus training with your own sets and reps), find the challenging weight intensity for the exercises in the video and cut back on sets and reps. Aim for one set of upper body work for 4-6 weeks and increase to 2 as you feel stronger. Even holding a barbell behind your back for leg work will place stress on the connective tissues of the shoulders and forearms, so take frequent breaks to put the weight down, pause the video, perhaps stretch for 15 seconds - and start up again.
Progressive comeback is key, but choosing weights that are too light will only make you want to do more reps and sets to feel the muscles working - and that might be counterproductive to long-term prevention.
Good luck! ;-)
-Roe