According to the Manual: http://www.olympusamerica.com/files/SP-510UZ%20Advanced%20Manual.pdf
Set your dial to "M" for manual mode
Use a combination of shutter speed and aperture for lighting and effect.
I don't know if you have a meter with notches/pegs but on the manual on page 13, there's a note showing Exposure Differential and a number. Maybe 0 means "Proper Exposure"
Shutter Speed and Aperture affects the amount of light on your image but they also do other things.
Shutter Speed: Fast Shutter Speed - Action Shot. Moving Objects that are sharp. Less Light -darker image
Slow Shutter will give you the blur affect. - More Light- brighter image
Aperture - The Larger the #, the smaller the opening.(at least on my camera) 2.8 has a larger opening than 8
2.8 would let more light in and vice versa
What this also does is affect your Depth of Field.
How much the foreground and background is in focus in relation to your subject.
The larger the opening(smaller #) the sharper the area will look and vice versa
You can compensate the shutter speed and aperture with the other's setting.
Say you want a action shot, but it will come out dark according to the meter. Set the aperture to a wide opening to allow more light in.
The meter isn't always right, play around.
Shoot over and under the "0"
smallbluepickles has some good advice, try out the other settings first and then move into manual. Especially the setting that lets you set the aperture.
take multiple shots with diff. aperture settings and compare them.