PHP Content Management and Themes

Unlike other OS CMSs, many of the best modules are paid rather than free, however there are loads of free modules as well. The cost is relatively low for most paid extensions and may be worth purchasing if it does the job and you don't want to code it yourself.

Drupal module review site. May be easier to find modules here than on the official site.

A tool to help you share and test your carefully constructed but for some darn reason not working code.

Create your diagramming approach using specific advice presented here.

This is required reading! Some very good information is presented in this chapter of the Web Style Guide.