Well, I don’t think I have actually written a post like that yet and I also think you may overestimate how many literal kids there are on tumblr - but since you’re handing out awards, here’s some gentle, non-judgemental info on masturbation like a good dad would offer if asked (since teens and young people deserve honest answers to make empowered choices):

Masturbation is a very common activity. It’s generally safe and healthy and it even comes with some benefits: 

• it’s only you, meaning there’s no risk of pregnancy or sexually transmitted diseases! 
• it’s a safe way to explore your own likes and dislikes and to try out fantasies you may have, without the emotional entanglement of involving another person (yet or at all). 
• it can’t break your heart. Sex with another person requires a lot of trust and communication and you shouldn’t rush into that just to try it out.
• it can be a fun way to get to know your own body, and knowing your own body is important to take care of your health! Knowing what’s going on down there is a good thing. 
• It’ll not ruin sex with a (future) partner. Many actually experience the opposite: getting to know your body and learning about your preferences solo actually makes sex with a partner more enjoyable and relaxed. 
• It may bring physical health benefits: it’s like a mini workout after all, plus orgasms are known to be healthy for you! 
• It can be a stress-relief and even helps some people sleep better. 
• It can actually help you live according to your values. For example, if you’re single and do not wish to have sex outside of longterm relationships, masturbation can help satisfy your needs without sacrificing your beliefs for a one night stand. 
• It allows you full flexibility without having to explain anything. You don’t like orgasms? You can just stop before you reach that point. You like to be perfectly quiet? Nobody expects you to moan if it’s only you. 

It also doesn’t really have any side effects or negative consequences in general. Ideas such as „masturbation causes mental illness“ or even „masturbation leads to blindness“ are outdated medical myths. There’s no scientific evidence for that at all and it comes from times with limited knowledge on sexual health plus very strict beliefs around „sexual purity“. Modern medicine considers masturbation a healthy activity most people do. 

Things you should keep in mind are just: 

• You should wash your hands before. While you can’t give yourself STDs (unless you touched someone else’s genitalia or fluids right before), you may have other germs or irritants on your hands that you don’t want down there. Also wash your hands after, that’s just basic hygiene and respect for the next person you shake hands with. 
• Masturbation doesn’t always require putting something inside of you. But if you do want to, please only use products specifically designed for that (or your fingers). Things that weren’t made for that purpose might hurt or injure you, or they could even get stuck or break off inside of you. 
• If you don’t enjoy masturbation, you don’t need to do it. While it’s a great activity for many, it’s still just an activity. Just like hiking or playing cards or singing: if you don’t enjoy it, you’re not missing out on anything by not doing it. 

Lastly, I also want to address this common question: 

Masturbation doesn’t always involve pornography. Many use their own imagination or even just enjoy the touch without any (inner) movie playing. You do not need to use porn to masturbate. 

But if (and only if) porn is something you’re curious about and maybe something you’re worried about (is it unethical or weird etc), please know: 

• it’s a very common thing to be curious about and it’s also something many people regularly consume. 
• Know that, just as with online content of other genres, shocking or extreme content sometimes gets the most clicks. This doesn’t mean it’s representative of what most people enjoy or want in real life. 
• Sex in porn is staged. It’s meant to look good, not be realistic. Be aware that it’s not a good source for sexual education. 
• The problems with the porn industry are mainly problems with the industry (such as unsafe working conditions, unfair wages etc.). The ethical problem isn’t the sex itself. 
• You can avoid some of the industry problems by seeking out ethically produced or fairtrade porn. This usually means: all workers were fairly paid, there were precautions taken that all workers are of legal age and are willingly participating, workers may get more say in which scenes they want to do etc. Those websites also often focus more on female or queer pleasure than mainstream sites do. You may need to do some research there but it’s worth it