If you open up Dreamweaver--then click on the help menu--you will see--Guided Tour | Lessons | Reference | Using Dreamweaver and several other good tools. You will also find a link to the Macromedia Forums Online.
There are several Dreamweaver Books out there but I have never purchased any of them.
They are video lessons and you can view the first couple chapters for free--and then decide if you like enough to buy them. They are from Mark Fletcher--a member of Team Macromedia. They look pretty good.