How can I make a View that shows the number of nodes attached to per taxonomy term? I want to list taxonomy terms to see how many nodes are attached to each term. 

I made a taxonomy View but can't find a field for the number of the nodes attached to per taxonomy term.

There is no this kind of field by defualt and maybe Views PHP or Views Custom Field are the way to go ??
This may help get you started. What you want to do can be accomplished by creating a views entity with a taxonomy argument that returns 'display summary when argument not found.'  In that setting as well is an option to display the number of nodes, (339) for example, that have that term attached to them.

http://drupal.org/node/301485#comment-1065230

Check out that link and post back with questions.