Can someone explain to me how fluids are simulated using particles? What equations to solve? How to update the particle positions? How awfully computer intensive is the algorithm? Can a simulation using a 100 * 100 * 10 grid run okay on the average computer? The more I read the more I realize how much is needed to calculate just ONE STEP in time.
What kind of simulation are you after? Are you looking at simulating "fluid-like" simulations that don't collide with any external geometry, or are you looking at doing a type of simulation of fluids in something like say a tank with dynamic geometry included? Maybe you should get started by reading about the Marching Cubes algorithm for the first case. There are plenty of demos on the internet for OpenGL and DirectX that show this (and have complete source code). If you want to do something with less constraints, then that is another issue.