How is this workout? also some questions!

[bmxunknown]

so questions... i heard that you can work your forearms 2-3 times a week because of extremely slow muscle fibers? but i heard that you should only work it out once a week ? so what is right?

and how is my routine, ive been working out for a couple months, but just started to take it serious...

* order is messed up

monday- chest. triceps.
-wide gripbench, 3x8
- flys, 3x8
-over head extensions - 3x8
-skull crushes 3x8
-close grip bench - 3x8

tuesday legs
-leg extensions3x8
-weighted calf raises 3x8
-lunges 3x8

Thursday back, biceips
rows, 3x8
wide grip pull up 3x8
close grip pull up 3x8
db curl 3x8
preacher curl 3x8
bb curl 3x8

friday shoulder, forearm ( not sure what some of the names are)
front raises 3x12
lateral raises 3x12
wrist curl 3x15
db upright rows 3x8

repeat. i dont do squats or deadlifts, or anything exercise that im bent over and handling weight. because i have a herniated disk and dont want to injure it more.

also im 17

how is that routine? i need some more exercises for shoulders and chest, and back, so if you can help me with that, thanks... also i work out at my house, so i dont have a lot of stuff.

[bmxunknown]

also, can i do legs more then once a week too, i have small legs, and want them bigger.

[bmxunknown]

....