If you are not one of those who always have a clear notion of what should happen in their novel, there are some methods that will help you develop the action based not on a plot but on the characters.
What does our character want?
At this point try not to focus on the external forces lying in wait around the character and his world. Starting a new job, the death of the best friend, a phone call from the president… these kind of things will surely offer the character something to do but the sense of a story is not to keep the character busy just for the sake of it.
The character must have an internal motivation, a need (which makes him start actions, search and move) besides an external motivation (which makes him react).
It is important to work on the definition of the internal motivation first. If you know your character you will have a clear understanding of his needs. You can be as vague as you want (perhaps he wants to be happy, find love, overcome his shyness); you just have to identify the part of his personality the character wants to solve.
Once you have an overall idea of what your character wants it is essential to constrict the focus to what could satisfy that need (a physical action, an object, an event, a thing). Perhaps it is a job, a person or a big diamond. Something tangible will make him feel better. Do not settle until you come up with something more representative that a temporary interest; it should be something strong enough or else your character will seem weak, going after something banal or easy to get.