Stata Commands
Here are several sites that have Stata commands you may find useful (by no means an exhaustive list):
University of Chicago, Department of Statistics http://www.stat.uchicago.edu/~collins/resources/stata/stata-commands.html
University of Oregon, Department of Economics (opens to PDF) http://www.uoregon.edu/~bruceb/Basic%20Stata%20Commands.pdf
Philip B. Ender, UCLA Academic Technology Services http://www.philender.com/courses/computer/statacommands.html
David Glidden, UCSF Department of Biostatistics and Epidemiology
Tips and Tricks for Your Analysis Project (opens to PDF) http://www.epibiostat.ucsf.edu/dave/biostat209/project-tips.pdf
There are some great examples and downloads on UCLA's Academic Technology Services web site (http://www.ats.ucla.edu/stat/stata/faq/whereplot.htm).