Today I am going to do a bit more explaining than I usually do about editing. I want you to know that EVERYONE makes mistakes. I don't care if you are an amazing photographer like Jasmine Star or my Grandmother who hasn't used a camera since 35mm film was the norm. Sometimes a shot won't turn out how you wanted and it's okay.
Today I'm going to talk about all too common under exposure/dark looking photos.
Whether you are using a DSLR or a point and shoot. Picasa has a great basic and easy to use setup to help you bring up your color and light without looking grainy.
For this particular photo I used a pairing of pulling up the "Fill Light", "Highlight" and "Color Temperature" and then added a "Glow" effect.
Make sure to go throw each step slow and see how you like the difference. Personally I pull up on a bit and skip on the another and come back to add a pinch more highlight or a tad less fill.
And the great thing is if you don't like what you get in the end there is a big "Undo" button waiting for you to try your hand at it all over again!
Don't let a dark picture get you down, besides when in doubt you can always claim you did it on purpose. What can they say they don't like your art... well it's yours so who cares!