well, let me tell you what worked for me...
i started with this 4 day cycle
day 1-chest
day 2-triceps and shoulders
day 3-back/biceps
day 4-legs
day 5-rest
now my 4 day cycle is:
day 1-chest, light triceps
day 2-back/biceps
day 3-triceps and shoulders
day 4-legs, light biceps
day 5-rest
i also do some cardio and alsosome abs and lower back...i would start out with the above plan if you choose to use either of these 2, except switch days 2 and 3 (so back/biceps is after chest)
i weighed 161 when i started this setup, now im 194. i have gained a little fat (read, went to college), but not very much (waist size went from 30 to 32). it really didnt take as long as i expected either...its different for everyone, but muscle weight comes fast.
as far as eating...eat a lot. drink alot of water. eat good stuff too: fish, chicken, vegetables, etc...and i'd recommend protein powder. dont skimp on the carbs either. these low carb diets are a bunch of crap if you ask me.
some suppliments may help. the only suppliments i have used are creatine monohydrate and protein. since you are still growing, i think you should not use creatine. for what its worth, creatine didnt do much for me anyway. i used it for 10 weeks, and did see some change, but not much. stay away from anything that promises quick lean mass gain, especially anything that claims to up your testosterone.
it is absolutely critical that you switch up your exercises every 6-8 weeks. if you do bench press for 6 weeks, do dumbells for 2-3 weeks, then go back to bench.
for mass gain: start with about 6-8 exercises per body part, and MAINATIN INTENSITY. listen to your body...if you cant maintain intensity for 6-8, then do less. use compound movements like bench press, SQUAT (absolutely critical), and deadlift. learn the proper form, especially for squat and deadlift. 6-8 reps per set is good for mass gain...but sometimes go higher reps (to prevent injury), and lower reps (to increase strength)...in fact, for the first month or so, if you havent lifted before, i would recommend higher reps per set (10-15)...just remember: low reps are great, work fast, but also have a high risk of injury.
edit: one thing i thought of...consider higher reps in the squat, and possibly the deadlift (8-15 reps)...i know that my knees cant handle much lower than 8 reps in the squat...i realize everyone is different, so again, listen to your body on this one.
be safe, stretch, and have fun.
sorry for the long post, but for me, this did exactly what you've described (gained about 30 pounds without getting fat)...
hope this helps!