Freepascal meets SDL should be your next source of information. We have learned much from this excellent site. Matthias Molski provides plenty of demonstrations and explains the code clearly. He also provides links to vital resources. We have mentioned before that set-up procedures are for Free Pascal rather than for Lazarus.
We have now included an impressive student program (Spaceshooter) developed with the help of the above website and Jason McMillen's Artillery tutorial available on the Pascal Game Development site and also republished here. Jason McMillen is Editor in Chief of Pascal Gamer Magazine, which aspiring student game developers should find inspirational.
Our final web recommendation is the NeHe Productions site. This provides impressive OpenGL demonstrations and tutorials. Their demonstrations are included in the download of Pascal header files.
Much of the SDL information on the web does not refer to Pascal, but you may be able to glean enough from annotated code in other languages such as C to help you with your Pascal code. (You will find some remnants of C code in the Pascal SDL documentation!) Our tutorial C/C++ after Pascal should help you to understand the syntax.