Website : I often find myself following outdated tutorials and using the online help system to see how things are done today.
From within Eclipse: Help > Help Contents
This is the only information that is actually up to date.
Use the website to provide links for others
Often can only be understood after you have figured it out

Book & Website : Quite helpful with the initial frustration of working with the Eclipse Framework. Helps when you just want it to work and don't care why.
Buy: if you use the above link more then twice an hour
Can be installed as a plug-in
The detailed code tips don't age well
I am going to buy the next version, not that we know when/if it is to be expected.

Book : Despite its title, and perhaps intent, this book covers a great middle ground between the the Contributing to and the FAQ books. Covers a range of topics, communicating the tricks that we would not have found otherwise.
SWT Layout tutorial with the same form done with each layout manager
Was how I finally learned how to use Viewers, LabelDirectors and ItemProviders
Only book intro to building offline with PDE Build / Ant
Content occasionally needs adapting for RCP use
The main benefit to us was that it showied the use of these technologies for real. I would really recommend this book as an alternative to the FAQ book if you can make it through the first month without being annoyed at your ability to update a status bar.

Book : A good reference (but so is the source code), I found the Building Commercial Quaility Plug-ins examples of using the SWT/JFace in anger more compelling.
Least used of all the books we bought