What part of your body do you get the shooting pains, and during which exercises? All? Some? Gotta give us specifics. Granted, we're not doctors anyway, and if we fail to help you (or if the pain is unbearable) you'd be better off seeing a certified medical professional.
20-30 reps is way too high. I'd keep the rep range between 5-10 if your goal is strength and size. You may want to try something Mark Rippetoe (a very gifted strength coach) devised for beginners.
You will train Monday, Wednesday, and Friday. You will focus on heavy, compound movements. The goal is to get as strong as you can as quickly as you can. The thing most people don't grasp is that, unless you're using AAS (in which case, all rules go out the window) you'll need to continually add weight to the bar (progressive load) over the course of time, while eating enough calories for your body to sustain the mass, in order to grow muscle. In short - focus on gaining strength, and the size will come.
Anyway, you alternate a Day A and Day B workout. The first week will go:
Day A (Monday), Day B (Wednesday), Day A (Friday)
The second week, obviously, will go:
Day B (Monday), Day A (Wednesday), Day B (Friday)
Here are the exercises to be done each day:
Day A
Full Back Squat - 3x5
Flat Bench Press - 3x5
Deadlift - 1x5 / Power Clean - 5x3
Day B
Full Back Squat - 3x5
Standing OHP - 3x5
Weighted Chinups - 3x5
You'll do three warmup sets for each exercise, then do your working sets for the same weight on all three sets. Here's an example - let's say you bench 135 lbs. You'll start out doing the bar (45 lbs.) for 5 reps. The second set, do 75x3. The third, do 105x2. Then do your working sets with 135 lbs. for 3x5.
You may need to use more warmup sets if the jumps in weight are too steep for you. This is fine. It may also be advised you do some like cycling for 5 minutes prior to warming up.
Squats are integral to this program! The main goal is to add strength quick. Every workout you'll be squatting. Try to add 10 lbs. to the bar every workout for 3-4 weeks. Once you feel you're close to stalling, drop to 5 lb. jumps each session. Continue with this. If and when you stall, drop the weight back 15-20 lbs. and ramp back up with 5 lbs. each session. If you stall, do it again. If you get stuck at your old weight three times, it's time to change something. The routine will no longer work for you. This is the premise, and the advice Mark gives. I'd follow it.
The squats will drive the program. Nothing else is as important. Make 5 lb. jumps with the other exercises each session. The point is to try to add weight as often as possible. If you need to, go to
www.paragonsports.com and order 1.25 lb. olympic plates, so you can make 2.5 lb. jumps a week, if need be. Eat a lot while doing this. Come back to us when you've stalled.
Oh, and the deadlifts and power cleans are alternated each Day A workout, but I figured that was understood.
And if you need to learn how to do these exercises, find a good coach, and order Mark Rippetoe's book Starting Strength.