Mike, do you have the manual? Those settings are for "Exposure compensation"
If the picture you are going to take is predominately white (like the 13 inches of snow here in Missouri), the light meter built into your lens will think the scene is too bright and will select a smaller aperature (lets in less light). If a subject (such as a person) is in the picture and is surrounded by snow your camera will under-expose your subject (too dark) and make the scene turn slightly grey instead of staying white. So you would increase the Exposure Compensation about one (+1). I'm assuming you are in the "Auto Mode" (point and shoot) and that you can change the Exposure Compensation in this mode. Many cameras will not let you set EC in the auto mode. Some cameras have a "P" program where you can change EC. That's why I wondered if you had the manual.
The other side is if the scene is predominately dark (like a black cat). Then the light meter thinks it is too dark and opens up the Aperature (lets in more light). The cat would then be over-exposed assuming the cat fills most of the picture. Again, this would normally happen if you are in the "Auto Mode". This time you would have to set the EC about -1 so the cat would look black with good detail. You can experiment to your hearts content cause the results will be right on the LCD and you can erase the ones that don't look right and start all over. Normally you don't have to worry too much about EC unless the scene is obviously way too dark or way to bright. By dark I mean shadows or a dark forest scene even though the pictures are taken during the daytime. Hope this helps.
Jerry
