How-to articles:

WordPressing dissected
http://cogdogblog.com/2008/02/14/wordpressing-dissected/
(the theme should look familiar to you)

http://lorelle.wordpress.com/2005/09/28/designing-a-wordpress-theme-from-scratch/

Making of a New WordPress Powered Site
http://cogdogblog.com/2007/01/16/making/

http://cutline.tubetorial.com/how-to-customize-your-header-images/

Themes

http://graphpaperpress.com/2007/12/09/gridline-news/

http://gridline.thadallender.com/
(I own the license to this template to use in an unlimited manner, so we don¹t need to buy it)

http://www.skelliewag.org/cream-of-the-crop-six-cutting-edge-minimalist-wordpress-themes-230.htm

http://www.smashingmagazine.com/2008/01/11/premium-wordpress-themes-are-they-here-to-stay/

http://www.smashingmagazine.com/2008/01/08/100-excellent-free-high-quality-wordpress-themes/