some links for drupal features and module development.
CVS
http://cvs.drupal.org/viewcvs/drupal/ has an example/browsable view of the drupal code & contributor code CVS system.
themes
http://themegarden.org/drupal50/ has some drupal 5 themes, though it seems the themegarden has recently been closed.
http://drupal.org/project/Themes has some screen shots of themes.
artists sites & groups
http://groups.drupal.org/art-music - this replaces the http://www.drupalart.org/ site.
CCK - Content Construction Kit
http://groups.drupal.org/content-construction-kit-cck - group for Content Construction Kit (CCK). this is the new system to replace flexinodes and allows you to create different fields.
http://drupal.org/node/101723 = Content Construction Kit handbook
http://drupal.org/project/Modules/category/88 - lists the different field types for CCK
Views
http://drupal.org/project/views - there's also a system called Views which are like database user views and allow different collections of information to be collected and then displayed once integrated into the theme. from this page:
"This tool is essentially a smart query builder that, given enough information, can build the proper query, execute it, and display the results. It has four modes, plus a special mode, and provides an impressive amount of functionality from these modes."
http://drupal.org/handbook/modules/views
theming CCK fields
theming individual CCK fields - http://drupal.org/node/62466
theming CCK & views to create a scheduling grid (good examples of how to customise which could be applied to other CCK node types) : http://groups.drupal.org/node/2647
http://oif.eafarris.com/cck_theming_in_drupal_4_7 - this is the site of the creator of freelinks module. he's using CCK on his site and shows an example of how he made and themed a custom version of weblinks module in CCK
tutorials & documentation
http://groups.drupal.org - for general info on different sections of drupal project
drupal video tutorials and screencasts -
http://drupal.org/node/124318
support @ bryght.com - http://support.bryght.com/
writing your own drupal modules
http://groups.drupal.org/drupal-dojo = a group for writing your own drupal modules with some lessons/tutorials
http://drupal.org/contribute/development has some ways people can help with drupal development
http://docs.drupaldojo.org/getting-started-with-drupal-development - there's a coding lesson coming up on 11th march. & they're working on a "Getting Started with Drupal Development" handbook
http://drupaldojo.com/lessons/ - has some of the lessons
http://drupal.org/node/508 - module developers guide
http://drupal.org/node/17914 - how to build drupal 4.7 modules
http://drupal.org/node/82920 - building drupal 5 modules
http://drupal.org/node/318 - drupal coding standards
http://api.drupal.org/ - drupal api's
http://drupal.org/node/49768 - drupal object reference
http://api.drupal.org/api/HEAD - examples from drupal head