I hav'nt read Wilhelm's three volumes yet. But saying about other books,
I think Stock's _The Life of Ezra Pound ( An Expanded Edition)_is
still essential, though it is not enough for the period after the WWII.
Carpenter's _A Serious Character_ is comprehensive for this period.
As for the period during the WWII, Redman's _Ezra Pound and Italian
Fascism_is very important. Redmans book is important also to know
about Pound's London years. As for this period, Tryphonopoulos's
_The Celestrial Tradition_ is very interesting.
Acroyd's _Ezra Pound_ contains many nice pictures.
For beginners, I think newly published _The Cambridge Companion to
Ezra Pound_is a good book. From this, adding to the introduction to
Pound's work, you can get many important biographical informations
in succinct form.
 
Hideo Nogami, Japan