I have HUGE boy problems!!?

i know like la ton of different guys and it seems whenever i first meet them either im to shy or it seems like i dont like them. I dont know why that is because im not shy at all (especially when im with my friends.) But then later when i see them i end up liking them and then by the time that happens it ends up that theyh only like me as a friend and its startin to get annoying. Can someone give me some ideas about how to like talk to them or how to like show that i like them and then later when i get to know them more then i can like them? please please please?