Your Q is normally the first thing you want to max out, But not in this particular case. the main reason you don't want to max it out first is because when you have to gank it isn't the most effective.
This is the second thing you want to max because it greatly increases your ability to sustain in the jungle. It also increases your damage.
This is the first ability you want to max because is gives you the definate edge when you are going in for a gank. this ability does true damage so no matter what its going to do the same ammount of damage.
your ult is great when you are in a sticky situation and need to get away. Also when combined with ghost it is really amazing for chasing someone down because of the extra speed and how it takes away unit collision. They have no chance of getting away if you use both your ult and ghost to get them.