ISOGAWA Yoshihito, who has already written  one NXT book and one Technic/Mindstorms book (both in Japanese), has released a beautiful LEGO Technic book in PDF format. The book is available for download; you are asked to pay $10 if you decide to use the book. The book shows a wide range of Technic mechanisms and small constructions. The mechanisms range from simple gear reductions to suspensions, clutches, and much more. The creations include many different vehicles and walkers, all fairly simple to reproduce. The book uses many different LEGO parts, some new (NXT motors, Power Functions motors and battery boxes) and some old (RCX motors, small pneumatic cylinders, the solar cell). In some cases, the book shows how to build essentially the same construction with two different kinds of motors or other specialized parts. The book covers basically all the kinds of mechanisms that you can build with Technic: gears, chains, pulleys, pneumatic, and so on. There is essentially no text, just pictures to illustrate principles and mechanisms. The graphics are beautiful, with clever icons to indicate chapters.

Browsing through the book will surely remind you why you enjoy LEGO so much!