First, download (the wonderfully talented) Pioneer Woman's Photoshop Actions.
Second, load them into Photoshop. If you have never done this before search your Help Menu for "load actions." This will be different for different versions of Photoshop.
Finally, open your photo and apply some actions by selecting the Action you would like and pushing the 'play' button at the bottom of the Actions toolbar.
I sometimes use Photoshop's Auto Levels command before applying any Actions, depending on the photo. I then start off with the Boost Action and go from there. It's easy to revert back to the original photo using the built in "Start All Over!" Action. (Makes playing around so easy!)
Here are some examples of photos I have enhanced using Pioneer Woman's Actions:
Actions used on this photo: Boost, Warmer, Quick Edge Burn
Actions used on this photo: Boost, Cooler, Lovely and Ethereal
Photo credits: My friend Kristen took these while she was visiting me this Spring. :-)
Note on software: Adobe Photoshop itself is fairly expensive (around $700) and meant for some pretty intense (and professional) graphic design and photo editing. Photoshop Elements is a much less expensive option ($80) and perfect for scrapbookers or people like you who just want to have fun with the photos you take. The Actions I linked to above are for Photoshop, however you can find the version for Photoshop Elements here.