So you can sensibly customise or style templates, the following page exists to give you a crash course in the standard templates.
These are the templates you are most likely to want to style
node.tt - The node view page
Is responsible for most of the display on the node view page, except for the core metadata (done by display_metadata.tt)
- google maps, if required
- node content
- nodes within distance
- geo (lat+long, x+y)
- rdf link
- old versions link
display_metadata.tt - The node metadata include
Displays the main metadata for a node page. (Doesn't do versions, or position - node.tt does those)
Supports the hCard MicroFormat.
home_node.tt - The home node page
Special handling for the home node. Skips the metadata, and shows the recent changes instead.
edit_form.tt - The edit node page
The main edit page. Collects all the information for an edit, and optionally also displays a preview.
These are other templates in openguides, but which you don't often end want to style / change.