Most Helpful Girl
I wouldn't be spooked by a guy saying he really likes me on a second date. It's true that actions speak louder than words, but I also like hearing "I love you" once a relationship gets to that point. That said, for as much as "I love you" on a first date would sound pretty desperate, the truth is that how I respond to a guy telling me he likes me (verbally or otherwise) doesn't depend much on when he tells me, it depends how I feel about him. If a guy is really interested when I'm not, it makes me uncomfortable; if he is really interested and so am I, it's exciting and reassuring to know.
Most Helpful Guy
I wouldn't say anything. It's too early, plus she already knows you like her because you're taking her on a date. As a general rule, don't tell her how you feel. Show her through your behavior.