How to watermark your photos
Open Watermark image, type your name, choose a position, and set the opacity.
Where to put it
Corners are easy to crop. Put it across something important, or repeat it over the whole image.
Batches
Add up to 50 photos at once, and each gets the same mark.
PDF documents
For a PDF, use Watermark PDF. It has the same text, logo and repeat options, and lets you pick which pages to mark.