I'm looking at using OpenFOAM for solving basic internal flows in CFD. What is the best way to get started, and could anyone please point me to a good online reference to go to with any questions I might have once I dive in? I've heard that it is quite niche as of now and many solver functions are not that well documented. Obviously the documentation that comes with the package itself is a start but is there a third-party reference (something like an OpenFOAM wiki)?
How to get started with OpenFOAM for CFD
fluid dynamics;openfoam
For running of  CFD simulations, I would suggest to start with the UserGuide and ProgrammersGuide. The ProgrammersGuide document features case examples as well, and it explains additional stuff such as boundary conditions. Using OpenFOAM on the top level is fairly easy, once you get a hang of the configuration files. Both documents are available in the /doc directory. Once you are done with this, you can find a lot of additional material from the Chalmers university: Chalmers OpenFOAM course organized by prof. Hkan Nilsson.When you are done with this, dig through the Wiki. Concentrate on the task you want to accomplish: the library is huge so there is no chance in getting to know it if you have a wide approach to learning how it operates. Work on specific problems, try to find documentation, engage in discussions on the forum and the extend project (see below). If you are interested in a specific problem, try to find out which solver is used to simulate this, e.g. for turbulent/laminar stationary solution, use simpleFoam, for transiert laminar solution, use icoFoam, etc. All of the solvers are saved in a directory structure that corresponds to their use like /multiphase/incompressible/les/interFoam would be a vof-like solver used for two phase Large Eddy Simulations (les). Start with running the cases from the tutorial directories. Always make a copy of the simulation case, so you can have the original (if you use git, and make a mistake, checkout the directory to revert to its original state). If you have made a successful instalation of OpenFOAM on your machine, execute alias on the comnand line and see that there are some nifty commands that help you get started: tut brings you to the tutorial directoriesrun brings you to the run directory: this is where you run your simulationssol brings you to the directories of the solvers... You can ask questions on the OpenFOAM Forum when you run into a problem, and there is a directory of PhD and MSc theses and articles on OpenFOAM available at the FAMENA (Faculty of Mechanical Engineering, Uni. Zagreb, Croatia) File Server.OpenFOAM Summer School is a really cool course organized by prof. Hrvoje Jasak at FAMENA, it takes place sometime in September each year, and it's a great opportunity to learn and get to know researchers working with OF. Also, there is a site organized by the OpenFOAM community: OpenFOAM extend project, where you can engage into discussion with people as well. Good luck! :) 