If you tell me more, I can give you a more specific guide.
For , the best guide is the official GraphicConverter 11.8 - Lemke Software GmbH User's Manual (PDF) , written by Hagen Henke. This manual is highly interactive, allowing you to jump to specific pages from the table of contents, and covers the wide scope of features in version 11.8. Key Resources & Tips: GraphicConverter 11.8.0 (5756)
The Lemke Software GmbH Forum is a good place to ask specific questions about version 11.8. If you tell me more, I can give you a more specific guide
For correcting architectural photos, select Effect > Live unskew keystone correction . Key Resources & Tips: The Lemke Software GmbH
Download the Manual_GC11_EN.pdf for the most comprehensive guide.
Note that the Mac App Store version has restrictions compared to the direct download version (e.g., no raw import for some formats, less filesystem access).
If you tell me what you are looking to do, I can provide a more tailored guide: or renaming files? Editing (unskewing, editing EXIF data, resizing)? Browsing and organizing images? Videos - Lemke Software