There is this boy in the year above me at school and I really really like him :) but he never notices me... :/
How can I get him to notice me & possibly like me back ? :/

Smile and say "Hi, [HisName]" whenever you pass him in the hall. If he has half a clue and has interest that should do it or at least get him wondering.

If he doesn't have a clue/interest, you might need to be more direct and ask him out.

Best way to get a guy to notice you is to do something spontanious
You could run up and kiss him on the cheek and say hey then leave
You could text him or find him in the hallway and ask him about some TV show or event
You could wave when you see him in the hall and that's it. Just a wave
You could tell him he's really good at something because guys like bragging
You could become best friends with his best friend then you'll see him a lot and eventually get closer
You could drop something on his foot but nothing too heavy then you'll talk a little
You could do something really funny that people start talking about and then he might mention it to you
You could join a club he's in, but that also you would enjoy
You could find him on Facebook and send him a friend invite

I think I covered all the bases for whatever type of person you are :) lol and goood luck

We need to know how old you are before giving you any advice. Okay?