Colour-management is an absolute minefield of a subject...
Rule #1 is to never adjust your images unless your screen has been calibrated first. You could well be doing more harm than good by doing so, moreso if you are shooting JPEG rather than RAW. (RAW files can always be recovered to their native state. JPEG files (usually) can't unless you have taken adequate back-up precautions to protect the original image file.) Most screens are set to be very bright, so when you view an image on-screen it looks nice & crisp; but the underlying image is usually a lot darker. There are many tools for calibration. The cheaper ones are basic, the more expensive ones will give you full colour control over your screen & output-printer...
Rule #2 is to set your camera to shoot in sRGB, if you have the option, if you don't sRGB will be the camera's default. IMO you should only shoot AdobeRGB if you're going to use the images for commercial purposes. The AdobeRGB colour-spectrum is greater than sRGB. So if you shoot in AdobeRGB and then print or display on a sRGB device (which all domestic & high-street printers & displays are), you run the risk of having some extremes of colour-range impacted... There's a good example of the various spectra here... http://www.repairfaq.org/sam/repspec/Cie-Chart.png
As for tools; here's a few;
- If you have an Adobe product installed you almost certainly will have the free Adobe gamma function. You can find it via the Control Panel. It's free. Therefore it's basic only.
- A decent entry-level tool for most users is Pantone Huey.
- Next up is Spyder. A very good all-rounder.
- Top of the tree is ColorMunki.
You can read all about basic colour-management and these tools here;http://www.northlight-images.co.uk/arti ... intro.html
and find links in the article.