ModuleTemplateSupport - how to add template support to a module
CodingATemplateFromScratch - how to quickly code inline HTML to produce a theme within Nukes.
ThemeStart - a quick way to create a template-based theme - no coding required.
The attachment below is a document I wrote for work describing much of the templating concepts for themes. It is tailored for intermediate Java experience to no Java background, so some things may seem tediously overexplained. It is 64 pages including examples, hope it helps. The document is available as .doc and PDF files whith the PDF having been reworked in terms of readability and layout.
Theme tips 'n tricks
HowToSetAThemeAsDefault - What to do, what goes wrong