Where to Find Help as a Wordpress Theme Developer

First fire up your browser and go to http://codex.wordpress.org. This is the home
page for the codex, where you'll spend a lot of time as a WordPress developer. The WordPress Codex is a user-generated set of documentation for the WordPress system.
Most functions and functionality are well-documented, and most theme-related questions can
be answered through careful browsing and reading.
For questions related to specific topics, it may be useful to consult that topic's page. Here is a
short guide:
Theme development—http://codex.wordpress.org/Theme_Development
Template tags—http://codex.wordpress.org/Template_Tags
Conditional tags—http://codex.wordpress.org/Conditional_Tags
Function reference—http://codex.wordpress.org/Function_Reference