Here are some suggestions of configuration for your GTKtalog. All the options are located in the preferences dialog : Settings->Preferences
Periodic saving of your catalog (Load & Save options). This is a good idea if you don't click enough on the "Save" button. This will prevent you from rescanning lots of CDs because you forgot to save your catalog in case of a power cut. To enable this feature, check Autosave and choose the minutes between every autosaving.
Keep a backup file (Load & Save options). With this option checked, you will always have a catalogfile.bak in the same directory as your catalogfile. The .bak is always your catalog file last running version. If one day the catalog file gets corrupted, you could always turn back to the ".bak".
Compression (Load & Save options). Adjusting the compression ratio of your catalog file can be interesting depending on your primary wish : size or speed. The more you compress, the smaller your file is but the longer the saving process. Choose the compression ratio between 0 (no compression) and 9 (maximum compression).
VFS. VFS stands for Virtual File System. It is a powerfull feature since you can navigate into any vfs that was previously scanned. The default Vfs are : .zip, .tar, .tar.gz, .tgz, .rpm (or .deb depending on your linux distribution [redhat like or debian like]). Choose the vfs scan mode that best suits your needs :
Do not scan vfs : if you don't want to scan the content of vfs files
Scan vfs : if you want to only save the files and directories names of the vfs (takes more time)
Full scan vfs : Same as "Scan vfs" but also stores the file sizes and last status modification dates (Same duration as Scan vfs ... recommended).
Submit the preferences box clicking on the "Save" button.