Sexual Relationships 
Sexual Health 
When it comes down to giving a guy oral sex for the first time, many girls find it almost intimidating. What are we supposed to do? Do we actually blow on it, suck on it, or...? How do we avoid it becoming painful for him?
Here are some of the most common rookie mistakes and how to avoid them:
1) No teeth. Nobody likes teeth being dragged up and down one of the most sensitive parts of their body. The fix is pretty easy. Wrap your lips inward around your teeth, like you may have done as a child when pretending to be an elderly person. Once you've done that, it'll be nearly impossible to hurt your guy at a time when he's expecting nothing but pleasure.
2) Use your tongue! Nobody likes their dick being brought in and out of a bottomless pit while no tongue is being used. Put your tongue to use in any way you can. Swirl it around the end or head of his dick. Flick at it. Think of the head as a lollipop if that works for you. Run your tongue up the underside of the shaft. You can do zig zags, swirls... anything goes as long as your tongue is actually doing something!
3) Be enthusiastic. Even if your technique is not up to par the first few times, if you look like you're actually enjoying what you're doing, your blowjob will be a lot more enjoyable than one from a girl who may have amazing technique but looks like she'd rather be anywhere but. You can show your man that you're enjoying sucking him off by being lively, trying new techniques on your own, asking him if the suction/speed/style is good, etc.. You can moan while he's in your mouth if that's your thing, initiating the blowjob on your own is great too. Once in a while, glance up at him. Can't go wrong with making a bit of eye contact!
4) Relax, don't overthink things. A lot of girls have the expectation of giving head that they'll need to bring pornstar level skills to the table, or they'll be one of those blowjob fails. That's not true at all. Deep-throating is not liked by all guys, generally is not all that physically stimualting for them and is more for the mental effect than anything else. It's also an aquired taste for both the give and the receiver. Don't worry if you can't get him to cum from oral alone. Different strokes for different folks... some guys require more stimulation to finish than any girl could provide through oral, others simply prefer to finish after sex.
As long as you focus on the first three points, you'll be fine.
There's quite a learning curve in giving your man oral. Every guy differs in what they like best, so every few times you can add a new trick to your repertoire, get to know how he likes things done best, etc..
As your confidence in giving head grows, so will his enjoyment of it. (pun intended)
Most Helpful Girl