Can anyone explain (in words, images, video) how to perform an ollie on a skateboard?
To ollie you need to do the following:
Take your rear foot (when I rode I rode goofy, so that would be my left foot) and place it on the tail of the board.
Place your front foot right just behind the front truck.
Stomp down with your rear foot. This is called the Pop.
Simultaneously slide your front foot forward and jump in the air. This motion should carry the board with your feet as you jump.
Here is a youtube video explaining it. Hope this helps.
To get higher ollies, I would suggesting resting your back foot on the very end of the tail and the front foot in the middle of the deck to allow for more slide. Popping as hard as you can and catching your board in the groove of the nose with you ankle practically resting in the groove will level the board out in the air. after this initial movement slide you feet back to the bolts on the tail and nose to ensure a clean landing.
Also keeping your shoulder inline with the board will help you stabilise yourself during the pop and in the air.