Lightroom was designed to mimic a lightbox, a simple device used to view film slides via transmitted light (light shining “through” the slide, as opposed to prints, which are viewed using reflected light).
Key to understanding the Lightroom interface is knowing that Lightroom is a modular program. The photos stay in the center area of the screen, while the toolbars on the outer edges may change, depending on which of the five modules you are using.
There are six main areas of the Lightroom interface. Some of these change as you perform different jobs within the program, while others stay the same, regardless of which module you have active.
You can hide or toggle off any portion of the interface, except for the Main Viewing Area. Doing so increases the size of the Main Viewing Area, giving you either more room to view more photos or a larger space to view the one(s) you have active. See the Tips section for each part of the interface for more on how to do this.
New to Lightroom 2.0 is the ability to work with a double monitor setup. It isn’t quite the same as Photoshop, GIMP, or the other “full-scale” editing programs, where you can place all your toolbars on one monitor and leave the second monitor for just the image you are working on, but it does provide a lot of the same functionality.
Fulfilling its model of a lightbox, it is also possible to change from a classic screen mode, with the menu bar visible, all the way to a Full Screen Mode, where only active photo(s) can be seen. In addition you can either dim or completely black out the things around the Main Viewing Area. Both of these functions allow you to focus on the shot without distractions.
After your first import, the best thing you can do is spend a good deal of time playing around with the interface, so you can hide, show, or otherwise manipulate it at will. With the exception of deleting files, Lightroom doesn’t actually “make” changes to the original file until you export, so mess up all you want. You’ll be more expert after every single thing you do wrong.
None at this time.