I get a fair few people asking me how I get the watermarking and avatar in my pictures.
Go to this site and download Fastone Photo Resizer. Don't worry all you cheapskates, it is a total freebie.
http://www.faststone.org/Once you get used to using it, you can make your pics the recommended 800x600 for web viewing, put watermarks all over them (I would suggest around 10% to 15% opacity) and crunch them down, but still be viewable, to very small sizes. Mine normally come out way below 100kb.
I learned how to use it by opening two folders on my desktop, one named 'old pic', t'other was 'new pic', very original.
Pop a piccy into 'old pic' and set the program up to load from 'old pic' and save to 'new pic'. Then play about to your hearts content, renaming multiple pictures so they all come out with the same name but with a different numbers following, changing fonts & sizes, even putting picture on picture.
After you get your pic exactly how you like it, the program remembers everything for next time.
I can drop a dozen pics in 'old pics', and seconds later they are all finished and awaiting uploading to my photobucket account in my 'new pics' folder.
Try it out, it costs you nothing, and you can get your pictures spot on for displaying on a website.
John