Mercvrii Trismegisti Pymander de potestate et sapientia dei
  A Translation and Commentary

This work is now available as a gratis open access pdf document: Mercvrii Trismegisti Pymander

It is also included - along with Translations of and Commentaries on tractates III, IV, VI, VIII, XI, XII, XIII - in my Corpus Hermeticum: Eight Tractates (pdf) of which a printed version is available: ISBN-13: 978-1976452369.