Solid base brother! Yes, the sets and reps are very important. As for the routine, Id go with more volume and variety. For back, Id go with a minimum of 15 sets. 5 exercises and 3 sets per exercise worked well for me. Reps between 12-15 to failure. Id give legs their own seperate day, since they should fully exhaust you. Id hit 12 sets for triceps and 12 for biceps. Split into 4 different exercises, 3 sets each. Might want to give arms their own day too. Shoulders can be hit on chest day, after chest, or even on thier own day. I sometimes do them with triceps. Id also add some inclines into your routine. At this stage Id suggest 6 sets of flat and 6 of incline with a few sets of flies afterwards. Some hammer curls wouldnt hurt either to bring up the brachialis and add thickness to the biceps. Keep in mind triceps makes up most of the arm when fully developed. You could even have a shoulder and trap day. I did that for a long time. You might want to try a split like this:
Day 1: Chest
Day 2: Back
Day 3: Triceps and Biceps
Day 4: Shoulders and Traps
Day 5: Legs
Day 6: off
Day 7: off
You can split the off days to fit your recovery. I guage recovery by how sore I feel. Basically Id go with 12 sets for smaller body parts like biceps,triceps,chest, and shoulders, and 15 sets for back and legs. This worked very well for me. Eventually you can make modifications to fit your recovery and preferrences. The only way to find what works best for you is through years of training and experimentation. All the auxillary muscles like abs,lower back,calves, rear delts, forearms and even traps can be added to the routine as desired.Here are my top choices for exercises:
Biceps: Preacher curls, Alternating dumbell curls, Standing EZ curl or Barbell curls, Various cable curls
Triceps: Skull crushers (on an incline bench, reduces elbow stress) , Rope pulldowns, V-bar pulldowns, Standing extentions
Chest: Flat barbell bench, Incline barbell bench, Incline dumbell flies, cable flies (Id reccomend 6 sets of flat bench and 6 of incline to start, with some flies thrown in to finish off chest)
Back: Dumbell rows, Lat pulldowns, Chin-ups, Barbell row,Seated Cable row, Deadlifts (Deadlifts gave me more lower back development and little upper back, so they are not completely necessary for bodybuilding in my opinion.)
Legs: Squats, leg presses(both for full leg work), leg extentions(for quads), leg curls,stiff leg deadlifts (for hamstrings)
Shoulders: Seated dumbell presses, Lateral dumbell raises, Various machine presses
Abdominals: Sit-ups on a decline bench (preferrably with a weight on chest),
Kneeling rope crunches (Hook a rope to the top of a cable machine, kneel down with it,contract your abs and pull the rope so that your elbows hit the floor)
Rear delts: Reverse fly machine
Forearms: Wrist curls with a staight bar, Reverse curls, COC gripper work, Deadlifts as well
Calves: Seated calve raises, standing calve raises
As for diet. Try to eat atleast one gram of protein per pound of bodyweight. More if possible. With your build, which is similiar to mine, Id reccomend you keep carbs and calories high. Its important to eat well above your maintenance calories each day as well. Most of all, be patient and consistent. The results will come. It just takes time, hard work, enough food and perserverence, which most people give up on. When I started training, my diet was terrible. I ate maybe one meal a day, moved furniture and bike 14 miles daily to get to the gym and back. I still made gains in size and strength. Mainly strength. Bettering my diet and eating more made a huge difference. Keeping a written journal of my meals and routines also helped me to do that, and motivated me to eat more. It still does. If you have the drive and heart you can take it as far as youd like. Being natural makes it alot more difficult, but it definately can be done. You just have to keep at it, even when it seems hopeless. It really does add up. You look real solid for 16 also. PM me anytime with any questions and Im glad to help!
Beast