GTDInbox is very easy to get going with, and it only has a few guiding principles:
- Labels are used to provide meaning to everything in your inbox - make sure you set them up right!
- If you cannot see it, try right clicking it (contact names, label names, emails)
- If you want something to pop out in a new window, try shift+clicking it (e.g. the Search button)
You can customise the Options, and reach the real 'Getting Started' guide, by following the links in the GTDInbox box at the bottom of Gmail's left-hand sdiebar.