Question on a630 and Flash

I am using a Canon a630, and can get fairly decent pictures outdoors without my flash...however when I attept to take photos indoors, the pictures never seem to come out right. Unfortunately I don't have an example on me now, but can post one later this evening.

I was curious however, what the -2-+2 scale is for adjusting the Flash, and how do I know which one to use?

Any other suggestions for improving with a Flash is greatly appreciated.

The scale on the flash is the same as the exposure compensation scale you'd use in regular, non-flash, shooting. If you want the picture to be brighter, adjust the flash exposure compensation to the + side (add light). If you want to get the pictur darker, adjust to the - side (subtract light).