How to tell a guy you like him?

Ok, so I have feelings for this guy. We don't really know each other that well, but I've known him for a couple of months. When my best friend found out, she told me that I should confess my feelings to him, but I don't know if he likes me back or not. We both run cross country and since the season is almost over, I won't see him as much (practically never). I plan on going up to him after the last practice and say something straightforward along the lines of, "I just wanted you to know that I like you...a lot." Is this ok? And how would he react? Thanks to all answers in advance!