Since I've been here for 3 years, I think it's alright to say which are the "Dos" and which are the "Donts" for a person who signs up in GAG for the first time, and what they should know about what's going on here.
(In alphabetical order)
1) Amazon Gift Cards can be provided anywhere in the world
Currently, we have 3 Rewards (GAG T-Shirt, TGI Friday's Gift Card, Amazon Gift Card). Amazon Gift Cards are perhaps the most popular reward here, but I've noticed many people think that Amazon Cards (strangely I've noticed some older users having this thought as well) can be provided among certain countries. But the truth is, they can be provided anywhere. They're just different stores, and anyone can buy from each Amazon store (USA, UK, CA, DE, FR), no matter where are they from.
2) Don't ask penis/boobs size questions
Most users here feel annoyed by those certain questions, because they're being asked many tiems on a daily basis. So it would be better to avoid them.
3) Gurus and Masters are not special members
I've seen many assuming how "cool" is this badge they have but actually it's not something important as it seems. It's a matter of how active they are and only. The more active you are, the more Xper you'll gain. There's only a small privilege though among these titles. Gurus can ask 1 question more than Level 2-9 users and Masters can ask 2 more. Apart from this, there's nothing special. See here as well.
4) If you are a guy don't send sexual messages to girls
Once you reach Level 2, and you are able to send messages, DON'T do this. It's not suggested for one main reason. You will have absolutely no luck if you attempt and not only chances are you will get blocked by those girls you sent messages, but you might get reported and have your account deleted as well. In other words, it's not the right site for those things.
5) If you are the oversensitive type, don't allow Anonymous answers
This is heavily connected, with #7 below. There are many people here who are usually being nice when they post with their usernames, whilst being mean when they use Anonymous feature. Of course not everyone's like that, but many are unfortunately. So my point is, if in case you're the oversensitive type, don't allow Anonymous answers, in order to get more nice answers.
6) Many people here are being fakely nice
Well it would be better if I said, Many people here are being fakely nice, when they post with their username. I already said above about it. Anyway, this is for those who are going to post in How Do I Look? topic mostly (but not only). Don't take any rating you receive seriously here, since from my experience, many people are actually giving higher rates than they would actually will. Also don't take this topic seriously, just post a picture of yours there for fun purposes.
7. Read the Help section once you start here
I've noticed many people here ask questions like Why can't I send messages? or Why can't I post any links? Your answers can be found here . As for how to find Help section, hover over your username on the top right. Help can be found second from last.
8) Take this site lightly not seriously
Silly to say this I must admit, since there are actually some people here who come here to seek for advice. I admit I'm not good at it personally, but there are people here who are good at giving advice when it comes to situations about Relationships, Marriage, Divorce, etc. But if in case you are here for fun purposes, then just don't take anything and anyone here seriously and don't take anything being said to the heart.
9) Try to write a MyTake
Many, new users mostly, often ask How can I gain more Xper? My answer here would be Try to write a MyTake better.
I believe it's a more productive way for someone to farm Xper, and you can write about whatever topic interests you, without any restrictions (as long as you are not rude or anything, obviously.). There's a further analysis about how to present a MyTake in order to make it Promoted or even Featured, which I will explain in another MyTake very soon.
That's all. Hope you like it here. There are also other things I didn't mention, but those are the most basic ones more or less. You'll find out more pretty soon, as time goes by.