This somewhat extensive modeling tutorial for beginners walks through the process of creating a simple triangle object with a circular hole through it. Even though the end result is a simple object, the tutorial covers many fundamental concepts such as active grids, constraint use (active grids, guides), basic polygon modeling, the use of normals and the difference between object and element editing.
NOTE: This is geared towards beginners, if you are very new and looking for more information about basic application use please visit the FUNDAMENTALS page.