VSO image resizer
is a great free tool with which you can resize and/or add a watermark to as many photos as you want with just a few clicks.
It is free to download the program for personal use.
Here is a tutorial to show how the program works:
1) Select as many photos as you like, right click on the selected photos and click on 'VSO image resizer':
2) to resize pictures you can either resize with percents or fill in the exact amount of pixels you want the image to be.
You can also choose if you want to make copies or change the size of the original picture.
3) To add a watermark to your pictures, click on 'effects' and then select 'watermark':
Then you can choose between using a picture or a text:
You can also decide where on the picture you want the watermark to be and the opacity of the watermark.
I hope this will help all the people who waste a lot of time resizing all their pictures with paint (like i did before i found out about the program)