As some of you may know, I'm 14 years old. I know I'm still growing, but I'm pretty...well, I'm skinny! :) So, are there any ways to build muscle, or rather, mass?

I know pushups are a great way to build one's upperbody, and I should get lot's of Calcium, and protein right? But are there any ways to gain muscle mass, preferably soon? The Spring season is coming up, and hey, I'm in highschool! :) I also know that just training hard, and practicing MA should help as well.

The doctor said that I have grown my full height, and all I have to do now is grow wider. I dunno, I think my body is developing strangely, but it's all just part of growing up. The weird thing is, all of the fat I have, has gone to my thighs, without "spreading". Yeah, I know, it's part of growing up, as I've said many times. Anyways, thanks in advance! :)