See Basic STGThumb Tutorial - Creating an HTML Album for a Flash version of the tutorial.
Using STGThumb is quite easy, just follow these steps:
1) Choose the folder where your pictures are. You can either type the folder or click on the folder button.
2) Click on Scan to view the pictures on this folder.
3) To the right side is a list with all images found. It also shows the folder, the image's resolution and the description, if available. You can click on a file to see the preview of that photo.
4) Choose the output folder. You can leave this blank, and it will create the album on the Start Folder, which is the folder you scanned.
5) Click on Convert, and the thumbnails and HTML will be generated.
6) The Album is ready! By clicking on the Open Checkbox on the Done screen, STGThumb can open the Album on your browser.