From both our personal experiences of our own varied sex lives, and in our work in sexuality with many other people, it seems pretty clear that really letting someone into an internal space in your body, or going into someone else's insides -- which we know might sound a little gross, but that is what's going on with this stuff -- is a fairly big deal for many people. So, what might make sexual entry different from other sexual activities?

Throw a rock at any sex education site or service, ask what the most common question we get is from men and we'll all tell you that it's about penis size. We don't imagine with this piece we'll never get asked again, but we're hoping these answers get you guys better filled in so you can feel good about yourselves, your penises and whatever you do (or don't) do with them.

Open, honest communication with your partners is key to healthy, beneficial and satisfying sexual experiences. Need some help learning how to make it happen and keep it flowing?

If we're going to think of our genitals as big, any one of us, given the small range between them, we should think everyone's genitals are big. We also need to accept that it's ignorant or misinformed to think, presume or suggest that penises are big but vaginas are small, because we really are all about the same size. If thinking big is better for one sex, it's also got to be better for the other. So, if you or someone else is going to go on about some big penis, you'd best get just as excited about the idea of a big vagina, and make having a big ol'Vagowski just as cool. And if you're all hung up on the idea that the vagina be as small as it can possibly be, or is such a small thing, then you've got to accept that penises are small, too.

Have a look inside S.E.X.: the in-depth and inclusive young adult sexuality guide by Scarleteen's founder and editor. Full table of contents and links to online excerpts.

Need a place to start in building your sexuality canon? Start at the bookstore or your local library, and get your read on with these books we suggest as cornerstones for a holistic, informed sex education!

The next time anyone tells you that only losers masturbate, or that they don't, and never would, bear this in mind: according to most studies and surveys, about 95% of adults have masturbated or continue to do so. Were many falsehoods and misconceptions about masturbation true, it would mean that 95 out of every 100 people would be blind, drooling psychopaths with hair on their palms and shrunken genitals.

Many people engage in oral sex, and find it a pleasurable of sexual activity. So long as you engage in it responsibly, it's just as normal, healthy, safe and natural as any other kind of genital sex. Here are the answers to some of your most common questions -- no secrets, no flashing lights and sirens, just the lowdown on going down.

You're forgiven if you think that even a little difficulty in this department means that you should start stocking up on Viagra. There are a number of falsehoods about ED floating around from schoolyards to saloons.

There's a reason for taking things slowly, for putting off intercourse, or taking it away from center stage that often gets overlooked. I'm not talking about slowing things down for religious or moral ideals or social pressures. Not slowing things down to prevent STIs and pregnancy. Not even slowing things down for legal reasons or because of your age. I'm not talking about Just Say No, and I'm not talking about not having sex at all. I'm talking about PLEASURE.

We talk a lot about sexual safety and safer sex here at Scarleteen in terms of your physical health. But what about checking in to see if sex is safe for you and yours emotionally? Taking care of your emotions, looking out for risk factors in advance -- not just when they become an existing crisis -- and safeguarding yourself, your partners and those around you from needless hurt and harm is just as important as doing what you can to prevent STIs and unwanted pregnancies.

When we look in the mirror as a culture, our tendency toward hysteria always seems to hover in our communal blind spot. We’re not very good at seeing when groups with a political or social agenda are manipulating us with fear, often the unreasonable, irrational fear of the taboo.