What should i do?

i have a really great guy friend that i have known since i lived in my house (about 10 years). our parents et but i never really got to know him until this year. all of the sudden he has started talking to me more and more and helping me with stuff while im working on my work in science.....like fixing my pencil sharpener. he's really great but i want our friendship to last, especially since we have just became friends. just today he came over to my desk after cl just to see how i was. and he waved to me in the hall after the grandparents/veteransday program (?) i think that he likes me...but im not completely sure. do you thinks he likes me? what should i do??