The list is short - I'll be adding more when I find time!
Tutorial: Batch Image Resizing Using FastStone
Should I Get Photoshop OR Lightroom OR ???
Well, it depends. You can even forget either and start with Picasa Image Editor - it's free & surprisingly versatile.
Adobe Photoshop: if you feel somewhere inside you're going to get --deep-- into post-processing, and you love the idea of working on images on your PC. An investment - in time and money.
Photoshop Elements, is not expensive at all. Even less than Lightroom. And it lets you learn in 3 stages of interface, beginner to advanced.
Adobe Lightroom: if you're more into organizing your shots, and doing some general post-processing. Mid-priced, and very popular with amateur photographers, so you'll have lots of people to talk to re: tips and tricks.