Nav design

hey guys, ive made myself the menu with slidebar that is featured in the tutorials but i have a few questions.

Once my buttons have been made how do i make it so on rollover they turn a different shade or colour, im novice in AS so would it involoe Onrollover?

Secondly, my object i have made for my slider doesnt seem to glide to middle of each button that ive made? can anyone shed some light on this?

i would appreciate any help

thanks

Kipper