Music man: Here's a teenager perspective. Quick story.
The setting: my friends basement
The time: The summer before 8th grade
I had just turned 13 when my friend Doug said "Yo I joined this weight lifting club at school. Wanna come over and lift?" Amazed, and not quite fully grasping this new idea, I replied "Yea sure why not?" Long story short, here I am 3 years later, in love with lifting and now training 4 days a week and I'm looking to add either a 5th day of agility stuff or just space it out over my two rest days. Then, I was about 5'6" 160 pounds of chunky not-so-goodness. Now, I'm 6' and 175 (I think my scale is crap, but I go to the doctor's tomorrow for my physical so I'll get what I really am then-hopefully more

) pounds of lean, muscular goodness with the abs starting to come out of their shell. Then, I was slow. I was tight everywhere: hips, hamstrings, etc. Granted, I was still a good athlete, but not that best I wanted to be.
There were a lot of stops on my quest of fitness. Freshman year, I plummeted down to 145 pounds at 5'9" I was madddddddd skinny with a full 6 pack. Surprisingly, I wasn't happy with it. My defining moment came during a baseball practice, when I barehanded a slow roller down the line and tried to sling it sidearm to third while on the run. My coach bluntly said, "You need to put on 10 pounds of muscle before you do that." So, this year I showed up 35 pounds heavier, and not much of that was fat. Granted, I grew another 2,2.5 inches, but thats still a lot of poundage. It wasn't fat gain, I could fit into medium baseball pants

while freshman year i couldn't even button them.
How I got there was a lot of eating, a lot. Good clean food: veggies, fruits, lean meat, eggs, etc. I'd have protein shakes here and there but mostly just post workout. So, I assume your goal is to put on some mass, as you are doing S2B. Myself personally, I haven't tried it, although I own the book and have read it a few times over. It's just not my goals at the moment. I know a bunch of people have done it here with some great success. The key is to eat; which I'm sure you learned when you read Dr. Berardi's section of the book.
OK, so I got kind of off topic and rambled a bit. The bottom line: no, I didn't shrink. I grew 6 inches in the 3 years I've been lifting. I believe some of that height came from the postural improvements that came from getting stronger. I don't slouch anymore and have pretty good posture. It makes you seem taller. I lost 15 pounds, then put on 35, dropped 5, now looking to put on more, hopefully until I catch bigDman at around 198 :p.
I highly recommend starting a log here to help keep you motivated. Myself, bigDman, and EdChap are all using the same program (EC's Ultimate Off-Season Training Manual

I think this is like the 3rd time today I've plugged it, and it's still only morning :p) and we're all about as far into it as each other. Ed and I are actually in the exact same spot. It's pretty cool to have 2 other people doing the same thing. It adds extra motivation for me since I workout at home alone. I'll think of slacking and then say to myself "Don't be a sissy. I gotta catch up to bigD and Ed" They're both ahead of me right now, which only gives me more motivation to push myself and get stronger.
OK, rambling over. Break time is over. Back to summer homework.