gBrowser Help: Quick Start Guide
Step 1:
Starting off
Launch gBrowser. A window should open. The sidebar (on the left) should be set with it's base folder being the "Pictures" folder in your home directory, or the root level of your hard drive if you have no "Pictures" folder. It is from this list that you choose folders and files to display in the Thumbnail Pane. The Thumbnail Pane (on the right) should currently be displaying the files in the base folder of the sidebar. If not, select the base folder, and it will.
Previewing different files and folders
Select a different folder in the sidebar. The thumbnail pane's contents change to match the new selection.
If you select a file, the Thumbnail Pane will attempt to display that file if possible. It can display images, text, RTF, and HTML files, and Quicktime movies.
Changing the base folder of the sidebar
You may have your images organized somewhere other than your Pictures folder. To change the base folder of the sidebar, select "Collection Preferences" from the gBrowser menu, and look under "Sidebar: Setup". From here you can set a new base folder. You can also use the "Change base up 1 level" and "Change base to selected" options in the Paths menu, or change the base to a selected folder using the contextual menu or by pressing command-down (and command-up will change the base up one level).
Previewing images
So you've set up the sidebar. Now select a folder that has some image files in it. Most likely, all you will see are the file's icons.
You will have to generate thumbnails for the files (or tell gBrowser to do that automatically from now on), or have gBrowser make thumbnails "on the fly" (without storing them).
To generate thumbnails by hand, select the files you wish to make thumbnails for and select "Create for Selected" in the "Thumbnail Images" submenu of the thumbnails menu. Hit start, and gBrowser will begin making thumbnails for the image files.
To have gBrowser do this automatically every time it comes across an image without one (or with one that is the wrong size), open the "Collection Preferences" again and check the "Generate automatically" option under the "Thumbnail Pane: Thumbnails", or select the equivalent item in the thumbnails menu.
If you want gBrowser to generate thumbnail on the fly instead of generating them once and storing them in an image's resource fork -- this is convenient if you are browsing through small (less than 120k) images whose files size you don't want to increase by storing a thumbnail and which are small enough to make on-the-fly thumbnails work at a decent speed -- choose the "On the fly" option under "Thumbnail Pane: Thumbnails".
Thumbnail sizes
You can thumbnail images at a variety of sizes by using the slider or textbox under "Thumbnail Pane: Thumbnails" in the Collection Preferences, or through the Thumbnails menu. However, be aware that if you have automatic thumbnail generation on, gBrowser will regenerate thumbnails every time you change the thumbnail display size! To prevent this, it is suggested you check the "Create thumbnails at size other than display size" box, and enter the largest size you intend to display your thumbnails at.
Other options
Go through the prefs now and check out the different options you have available to you. While the basic functional style of gBrowser cannot be changed (if gBrowser's style and the organizational scheme it encourages does not fit your personal style, there are plenty of other types of image browsers/organizers out there for you), I have tried to make the appearance quite customizable. Play with it, see what you like.
Note, the more info you choose to display about each image, the more info gBrowser must look up about each image, so thumbnails may appear to load more slowly.
The toolbar also contains a number of interesting features you may like. Most importantly, you can add folders to it (just drag them onto it). Clicking on these folders will change the base folder of the sidebar.
Step 2:
Finishing up
Now that you are finished using gBrowser today, it is time to save your settings. Hit command-S or choose "Save gBrowser file" from the file menu and save the file somewhere convenient (like your Documents or Pictures folder).
What is this file for?
This file saves the settings you have just chosen; this allows one user to have multiple setups available just by double-clicking the appropriate file. You may, for example, want to have a "pretty" setup with a large thumbnail display size and image shadows for general use, and a "quick and dirty" setup with smaller thumbnail display sizes and no cluttery, distracting appearance options for those times you want to search through a large number of images quickly. Or you may wish to have different setups for your personal pictures and your work pictures, with different thumbnail sizes and a different base folder.
Default setup
You may want to have one particular setup that is either the one you use most or the only one you use at all. To have gBrowser open up your default file on launch instead of opening a new untitled window, go to the default preferences (in the gBrowser menu) under "Launch: Setup" you may choose a file as your default.
You can also set hot keys in the default preferences. These are used in image windows, slideshows, and the Image Viewer.
The other default options mirror the window options you were playing with earlier; these options determine the default setup for new, "untitled" gBrowser windows.
Step 3:
Rinse and repeat.
Oops, I mean there is no step three! Enjoy!