Right now I go to the gym mon wed and fri and only lift upper body. I do the same excercises on all three days which usualy hits my shoulders, biceps, chest, triceps, forearms and lats. But then I read somewhere that you should give your muscles 4 days of recovery period. Currently mine get 2. I am going for mass should I maybe split it to where I do chest/shoulder say on monday then biceps,triceps,forearms wednesday and just alternate the two? If thats what I do on a chest day should I do incline,flat, and decline bench? I really dont want to hurt myself so im hoping someone here can shed some light! Thanks

No, it ok to train your uscles after 36-48 hrs as long as you control the volume you lift. ie you don't want to overload your CNS to a state where it needs a week to recover which is what happens if you do high volume training.

I would however say you need to train your legs and lower back. Your legs are your biggest muscle group and will produce the biggest overall mass increase (not just on your legs) when they're worked, and your lower back is essential in body stabilisation ("core stability") which will give you better posture, less chance of injury etc.