An interesting book, certainly, and as it says invaluable, take a good look.

Product Description
Legal Opinion Letters Formbook is an invaluable resource when you need to render a legal opinion letter on topics from commercial transactions to real estate lending, intellectual property to insurance coverage, securities law to corporate status, and much more. This one-volume guide provides you with: – More than 60 comprehensive illustrative forms prepared by leading experts in their respective fields – Chapters written by 22 noted experts – Clear ex… More >>
Legal Opinion Letters Formbook, Second Edition