http://www.puberty101.com/ or http://www.puberty101.com/p_breastsize.shtml 
 Go to the website and read some of the material. Wikipedia only allows creditable and on topic relative sites that are not user generated or judgmental. that's why we don't have anti-jew sites in the jewish article(s) at least i hope we don't. 

 its has someone who gets asked questions and they answer the questions in unprofessional and judgmental ways. 

 Q  	   	 Tim (12-14) asks... 

 When my sister gets out of the shower and goes into her room to change I watch her masturbate. There is a hole in the door and I can see right between her legs and sometimes she sticks things in her vagina. Is it OK for me to do this? Is it normal? 
  	  	   
 A  	  	 Tim: 

 Well, your curiosity is perfectly normal. However, I don't think it's okay. First of all, masturbation is a private moment. Second of all, it's your sister  that's not too cool. I suggest that that hole in the door be fixed and you respect your sister's privacy. 

 Q  	   	 Brian (15-17) asks... 

 When I am in Gym, I take a look around at other boys undressing and I get my penis gets stiff. When we are in the shower, it gets even stiffer. I'm not gay, but why is it doing this? 
  	  	   
 A  	  	 Brian: 

 You're getting erections because it turns you on to see other boys undressing, and it turns you on to show them your own penis. Many people (gay and straight) get turned on by sexuality itself, regardless of the subject. True, you may not be gay, but I wouldn't totally rule it out. You should explore in your head what really does turn you on. And like I mentioned to Ryan, above, perhaps you should consider avoiding putting yourself in that situation. 

 Q  	   	 Matthew (15-17) asks: 

 I masturbate 3-4 times a day in private, and maybe once or twice with one or two of my friends. The thing is they only play with themselves once a day, am I normal or am I some kind of sicko? 
  	  	   
 A  	  	 Matthew: 

 Well, as you can read from the other responses, masturbating a few times daily isn't necessarily bad unless it gets in the way of other activities. Now, I assume you don't mean that you masturbate with with your friends every day also? I guess that wouldn't necessarily be a bad thing, but at this point, masturbating 4-6 times per day may be taking time away from other activities. You are probably in the normal range, although most boys don't "circle jerk" that often as they reach their late teens. If you're obsessed with masturbation, or masturbating with your friends, then perhaps you should take up a sport or hobby that will give you something else to do also. 

 at the bottom it even has a disclamer 

 Disclaimer: Answers to questions should not in anyway be considered as professional advice or used as an alternative to seeking