Well, it's a really interesting part of photography you just picked out here ;) First of all it depends on how good the metering in your camera is. That's basically where a problem with exposure starts. If you know you can trust your metering system in most situations (there are always some extreme situations ofcourse that no camera can handle really well :), only then you can use your exposure compensation to manually correct your camera's readings. I'd do it like this: Find some very boring average sitations, preff. outdoors. Make sure you're not shooting into the sunlight, and take photos on manual, using your camera's exposure readings. Just shoot away....your house, street, etc. Also use the 2nd half of your roll for shooting single objects. Make sure they're in the center of your photo, and shoot away....portraits might be best (or statues, street signs, etc, anything which is loose from it's background). The simple trick is, if you use your camera's readings, you can check how the metering works....see if your photos are well exposed....if they are not well enough exposed it's good to see if they are all under/overexposed, or if it changed per photo. That's basically a simple way to get to know your camera. As soon as you sort of have an idea of wether it'll meter the situation correctly or not, you can set your exposure compensation. It's also great to do this in series, which will show you how great the effect of the compensation is. Personally I always underestimate the difference + or - 0.3 makes on a photo. So if yours works the same as mine, you'll really never use the 3 :P So, like I said, it all depends on your camera's metering. As soon as you've figured out if it's very good or not, and if it's not, when it makes mistakes, you can start using exposure compensation. Otherwise it will just be a wild guess :) Hope that helps ;)