I just bought Inside 3DS Max from 1996, but I have 3ds 5.0. How much has the interface acutally changed and is this book even going to help me?

I''m not familiar with the book you mention, but I do know that I''ve never had problems upgrading from one version of MAX to another. Ofcourse, things are placed somewhat differently in the gui, but you should be able to figure where stuff''s located within a short period of usage.