Vert = speed strength
Oly. lifts = strength speed
Deadlift = absolute strength
Deadlifts and squats are important for developing the muscles involved in jumping but oly lifts will train the muscles more specifically.
If you have a pretty solid base to work with (squat ~1.5x bodyweight with good form) then start working on simple oly. lifts (power cleans, high pulls, hang cleans) and then start an intensive plyometrics routine before the time when you need your vertical highest (combines or meets). You could do mild pylometrics through out your training (bounding, skipping, jumping).
You might want to check out DeFranco's quick tips for a higher vertical (or something like that) to help you tie up some loose ends.