Good tips for beefing up so far, and you should definitely look into them. One thing you should focus on, perhaps even more than bulking up, is your technique. I'm sure the smaller players on this forum will agree, like me, that technique is very, very important. Especially if you're gonna play in the back line. You will dominant a player if your technique is better. Believe me when I say I understand where you coming from on your light-weight issue (no pun intended
). I was an inch taller and one or two pounds heavier than you at age, but I was the first pick open-side flanker at my school, who was the 1st choice jumper (they basically grabbed me by the shins) and vice-captain (captain for the forwards since our captain was in the backs). Most of my coaches will agree that I was just a freak of nature but I enjoyed a kinda successful and very enjoyable high school rugby 'stint'. I relied heavily on technique during those years and it worked. It depends how far you taking this though, high school rugby is definitely more chilled than club so I take it you doing it more for fun. So DEFINITELY get the basics down before you concentrate on bulking up, but by all means get your fitness up. The more experienced rugby player will notice bad technique from a mile away and will make you his target, atleast I did. I agree with you on playing wing but also give scrum-half a try, if it makes you feel better you and George Gregan are about the same height
. If you can 'spin' pass both ways without changing your body position you'll be perfect at scrum-half. Play some more 'touch rugby' with your mates everynow and then, it improves your passing, agility and vision (awareness of whats going on around you) tenfold.
Lets us know how it goes, high school rugby is alot of fun.