I had another look at the USGS web site, and on it found a large compressed file containing Powerpoint notes from a short course on how to use PHREEQCi. I've loaded some of the decompressed files on the NDSU web site, at:

Course Notes for Phreeqci

The original compressed file is entitled "Notes for training course: Geochemistry for Ground-Water Systems (GW3O21.tar.gz, PowerPoint and examples, 12M)" It is located at the USGS web site "PHREEQC (Version 2)...": <http://wwwbrr.cr.usgs.gov/projects/GWC_coupled/phreeqc/>. Not all files are included here (the .doc files, for example).

There are separate files for Solutions, Reactions, Inverse Modelling, Transport, and Sorption & Kinetics. I'm sure some of these will be useful for the term projects you're working on.

The "notes" panes in the Powerpoint files often contain useful information, so be sure to check those out.

Thanks to D.L. Parkhurst and the authors of the Powerpoint files for making these files available on the USGS web site.