I can't help you on your first part. 

Red: What you do is drag Ruby around. Once he goes completely clueless, you know there's something about a relationship. He doesn't get that kind of stuff at all.

^Like Red is so much better.

If someone has a crush on you.... hide in the bunker. Here, I have room in mine, I'll share it with you.

I'm kidding of course.

If someone has a crush on you, it's best to be polite as possible. If you like them, then do whatever you kids do when you like each other. (I really am clueless, huh?) If you don't, please be polite and try not to hurt their feelings, but pretending that you do like them isn't good for anyone in the long run. In all the books where that happens, it always ends awfully. 

And that is the extent of my knowledge. Whew! That's over. 

Uh, well most of the guys that had/have crushes on me always stare at me. Non stop. But others completely ignore me, or throw stuff at me and make me want to rip them, limb by limb, apart.

I would give you the same advice that Ruby M. suggests. (The last paragraph ; ) 

But my BFF has this thing called her "Two Mile Radius" where if her crush is within those limits, she acts insane. Not by her own will. (It's a bit scary, really) 

I don't have a ton of expirence in this area but if both like each other and are interested in having a boy/girlfriend, then let them know that you like them! If you don't like them back, then don't to anything, just don't lead them on. 

Some signs that they like you could be:

Making an effort to be around you, even if it's just sitting near you

Talking to you and laughing at your jokes a lot. This one may not apply if the person is shy.

It all really depends on the person, I think. If you think they like you, then it's highly likely that they do. 

This is kind of random, but are you a boy or a girl?  

Sorry, I was no help! 

I can't help on the second part, because I don't understand human beings. (Even though all physical evidence would suggest that I am myself a human.) But I'll try to help you with the first part.

If someone has a crush on you, they'll act differently around you than they do with other people. For example, if they're usually really sarcastic they might be nice to you. They'll go out of their way to hang out with you. They'll probably smile a lot around you (even if they don't usually smile, like me). They pay attention to what you say and remember things you've said in the past (even insignificant things, like your dog's name). They'll also act awkward around you, and they'll be kind of fidgety.

Okay , this could go a whole bunch of different ways .

It depends on a lot of things . 

Do you like the person back , age , are you allowed to date etc... 

For guys , usually they mess with you . Younger guys usually act mean , and older guys clown on you a lot and flirt .

Like this one boy that I liked ( he liked me too but I can't get in to all this because it's too much to explain  ) liked me back . At the time he was 15 and I was 13 .. He like looked at me a lot and he clowned on me NON STOP . And he flirted A LOT . So we started texting and I told him I liked him and come to find out he was crushing on me too ! But honestly , with stuff like that , it's all a risk .... 

If a girl likes you , usually she's like really shy around you and is really flirty . And she'll stand by you or sit by you but she won't dare to make the first move .. The easiest way to tell if a girl likes you is a.) how she acts around you and b.) if she texts you everyday and uses smiley faces a lot ... 

If you like the person back , tell them ! If you don't , tell them ! 

Hope this helped . I haven't had many boyfriends but I've talked to a lot of guys ( and they've all been older ... so my sage wisdom ? Unless you're ready to get your heart ripped in shreads DO NOT mess with older guys or guys in general . STAY AWAY until you're older ! The fact that you're asking this question gives away you're probably under 14  and not ready for a boyfriend/girlfriend . Trust me I had my first boyfriend at 12 and he was 15 .. and I'm STILL getting over him . So don't get involved until youre ready ! Sorry for the rant ! Lol )

Here is some help, and questions to aks to yourself........ Does he/she strae at you often? Does he/she smile at your jokes? Does he/she talk to you alot? Does he/she ask for your guidance? Does he/she feel shy about you? Do you guys share commen intrests????

If you think someone has a crush on you, do you like them to? If you do, just wait for the proper moment, and I would NOT suggest if you are unsure walking up to them and telling them you like them. If you dont like them, dont telll him/her you dont like them, because they have not approuched you yet. If they talk to you about having them have a crush on you, kindly say I am not allowed to date, or say I am sorry, but I dont think it is going to work out.

I hope this helps!!!! 

Quite frankly, I need help in this department too. Cause... lets just say the school dance is coming up and it will get interesting.... namely because of a certain boy who DOES NOT DANCE...