From what I can understand about Japanese culture, "moe" does indeed refer to "turn-on" (Lucky Star is probably what taught you that XD) It's not always sexual but it normally refers to "fetishes". "Kawaii" can literally describe anything that is "cute". But "moe" and "kawaii" are not the same. For example, a Japanese girl would call a puppy, clothes, or flowers "kawaii". She would not refer to them as "moe". A Japanese man would call a maid, a schoolgirl, or a bishoujo figure "moe". But he could also call them "kawaii" as well.
Does that help?
