You have a few choices to make.
You can set up your D3000 to capture images as Raw data files, or as JPEG image files.
Raw data files have the most image information, but they are not finished photos and have to be developed using image editing software. But, you have complete control of the final photo.
JPEG developes the photo automatically, but you have little input how that is done save some crude adjustments. In your camera menus you can increase the saturation applied to the JPEG photos the camera makes. You can also adjust the contrast and how much the photo is sharpened. See page 87 & 88 (Shooting Menu - Set Picture Control) in your D3000 users manual. I believe the complete D3000 users manual is on the white disc that came with the camera and is not the paper quick quide.