In case you're unable to locate official instructions regarding how to implement WordPress Theme Options they can be found on the "Theme Customization API" page. Since the Codex, for this section, is not well written you may want to consider this unofficial article on TutsPlus.

Here are the pages I looked at first but were inadequate.

• http://codex.wordpress.org/Theme_Development#Theme_Options
• http://codex.wordpress.org/Creating_Options_Pages