Am I doing this right?...

[redbulladdict]

Hi guys, was wondering if I could get a little feedback to my whole workout routine. Total noob here, so be easy on me.

So I've been working out for 2 years (was off and on a year before that, but seriously started getting into it a couple of years ago.) The problem is, I'm not exactly sure if I'm working out correctly or not. So, the basics: I'm 5'8", 158, 30" waist, 46" shoulders, 13.5" biceps.

Before each work out, I do 20 minutes of cardio on the bike (I start out at a low resistance level,6, then alternate between high and low..6 & 10, then end with a relatively high resistance, 12). Afterwards, I start on the bench-press (this one is different from the one I'm used to though, the back is raised slightly so it looks like you're sitting on the bench). I do a set (12) of 125's, then do about 2 sets (I only get through 6 reps) of 145. Then I do 3 sets (9-6-6) of squats at 185. I take about a minute rest, try for less, between each set. After this, I do a bunch of other Nautilus training stuff (abs, back, leg extensions) at ~130-140 pounds, 3 sets (12 reps) of each. Sometimes do more/less nautilus depending on how I'm feeling. After the nautilus, I go back and do the bench presses/squats again, the same number of sets/reps.

As for my diet...gotta be honest, I could put more effort into it. It mostly consists of high carb high protein food, and I drink way too much soda/juice for my own good. I drink water also, especially after workouts (usually go through glasses), but non-water intake surpasses water intake by far.

Now, my question is...apart from my diet, what other aspects of my workout can I change to get bigger biceps and thicker calves? The cardio seems to help a lot with losing body-fat, but is the bike the optimal machine for cardio or are there better alternatives?

Also, ever since I've started lifting, my back has been *killing* me. It's a certain spot on my upper left side, right below my shoulder blades. It dawned on me (duh..) that this probably means I haven't been lifting correctly, and this is true...during my first year I had horrible form and sometimes lifted too much (blame it on deciding to work out alone in my school gym with no-one around to spot). However, even after taking a month break at the beginning of this summer, I've found that the back problem is still there. Anything I can do to solve this, or should I just go see a chiropractor or something?

Thanks in advance

Edit: Forgot to add, I workout 4-5 days a week, same routine (just been reading up and discovered using the same routine is not the best option).