Well Ollie is a basic "jump" on a skateboard.
You MUST know how to Ollie if you want to be a good Skateboarder
You can thrust me about my instructions, i am PRO skateboarder, i skate since i was 3 years old, and i can land almost EVERY trick, even 900 flip (you will learn soon what 900 flip is)
Step 1: Foot position
You want to place your front foot right on MIDDLE of the skateboard, and you want to place your back foot on TAIL of skateboard - or for beginners: you want to place your back foot at the END of skateboard
Step 2: Jump
When the tail hits, slide your front foot up to the nose, while picking your knees up towards your chest.
This will force the tail of the board into the air with you.