Eva,
PhotoShop Express will do it for you very easily. It’s not that expensive, and simple to use. I’ve processed hundreds of photos at a time for web upload. It can even make thumbnails and web pages for you at the same time.
Although I haven’t used it for auto-processing, Picasa (free from Google) can apparently also be used. See here… https://support.google.com/picasa/answer/19601?hl=en I’ve used Picasa for individual edits in the past and it’s easy to learn/use.
Enjoy! If you need tips, you know how to find me, just let me know. 🙂
-Chris