1) Online from www.eclipse.org/documentation/. For example "Eclipse Ganymede Documentation (HTML Help Center)" is for Eclipse 3.4.
The same documentation is available from Eclipse menu Help -> Help Contents.
Start with Workbench User Guide chapters Getting Started and Tasks.
Really usefull and relaxing is the Tips and Tricks chapter.

2) If you have installed the platform, you can always take a tour from menu Help -> Welcome.

3) There is no experience compared with practice, especially for GUI intensive apps.

4) You can browse for more resources in the Eclipse site www.eclipse.org with good articles and responsive comunities available.

5) Be prepared to discover nice functionality all the time. From time to time we recommend to read tips, tricks or concepts.

You can access it by Help> Help Contents and Eclipse Help System is opened. The DVT Help is just another chapter inside Eclipse Help as the image bellow shows:

Use Ctrl + Shift + L to get the list of all shortcuts.

To configure go to menu Window -> Preferences -> General -> Keys in the Modify tab.
From the Modify tab you can also select the built-in Emacs scheme. Depending on the installed plug-ins, you may use other Emacs / Vi emulations.

Related plug-ins:

• ETEE for Eclipse Text Editor Enhancements
• Columns 4 Eclipse or Column Mode for Eclipse for rectangular selection
• Lunar for editor enhancements
• ViPlugin for vi emulation

Right click on a file in the Navigator, from the pop-up menu select Compare With > Local History.
To configure the history go to menu Window > Preferences > General > Workspace > Local History.

Problem: I'm unable to select an existing workspace after my eclipse program that was accessing it was not shutdown properly.
I get a "Workspace in Use" error when there are clearly no other eclipse instances running on my machine.

Solution: If you are sure there is no eclipse looking at your workspace (not even another user), then you must remove the lock file located in the workspace at path_to_workspace/.metadata/.lock.

On Windows, if you cannot delete this file (because another process is using it), then close all eclipse IDE sessions, do Control-Alt-Delete to bring up Windows Task Manager, select Processes page, and delete javaw.exe.