Starting with View Modes
You should take a look at Display Suite.  It makes easy work of most template modifications without having to create .tpl.php files.  It has an easy to understand method of managing View Modes.

From the above link:

Use custom view mode


Enable DS UI module.
Go to Administration > Structure > Display Suite > View modes (admin/structure/ds/view_modes)
Click "Add a view mode"
Enter a label &amp; define to which entities the mode will be made available
Click "Save"
Go to Administration > Structure > Display Suite (admin/structure/ds)
Click "Manage display" for the entity (e.g., "User") whose display you like to change
Choose the vertical tab "Custom display settings"
Enable the new view modes
Click "Save"
Flush all caches
Choose the custom view mode from the secondary tabs in the top of the page.