Thank you! I’m so glad you like them!
I just use Photoshop CS5 for my photo editing. I usually don’t change the color much (though sometimes I increase the brightness), but I always add the watermark to try to deter theft and increase awareness about where the images originate from.
If you’re a student and can prove your enrollment (through transcripts or something of the sort), you can get Photoshop and a few other awesome Adobe products for about 80% off. It’s a ridiculous deal, and if you’ve got the money to spare (just over $250), you should really consider it. Photoshop’s not going away any time soon and it’s an unheard of deal for students.