Did you just watch the Monkey King? I love that movie!
Anyways, you have an idea, now start skimming out your characters and world.
Who wants to find the monkey king? (characters)
Why do they want to find him? (fame, money, bounty, truth, answers to life)
Where are they now? (Earth, the moon, the ninth level of hell)
Where are they going (antoher realm, dimension, ect)
What will they do when they get there? (kill the monkey king--he smells bad andyways. Capture and enslave his powers? Release him from a prison?)
But more than the setting, a story need characters. If you are looking for the traditional, which is my favorite, look for fleshy characters with inner turmoil and pasts that may still come back to haunt them (think Dragonlance) If you are heading for a neo-traditional, think commerce, power, education, unfailing resolve to complete the mission (think Forgotten Realms, Elminster, Cyric, ect)
What I do is I first draw a map. A very simple and 3rd grad rendition. Then I draw people. I sketch out their physical characteristics, history, and desiress---both external and internal. This requires a lot of self-analysis too, I like to make characters that are like me, and ones that are the opposie of me.