Views page list of all content grouped by taxonomy term
Here's how you would go about doing this:


Include the tag you want to group by in your fields (see map)
Click on your format settings. (see map)
Set grouping field to the tag.
Set exclude from display to true in your tag field.


That should get you to where you want to be. 

Here's a map of where 1 and 2 would be located.