What are the optimal settings for my digital camera? I have a brand new Canon PowerShot 12.1-Megapixel Digital ELPH camera, but I've been really disappointed in the quality of pictures it takes. For example, sometimes there are these smallish blurred white circles on the pictures. Can you recommend optimal settings that I should be using? I use my camera indoors and occasionally outdoors, so whatever settings best cover all different conditions would be ideal.

Small white circles usually means dust on the lens.  Remove the dust with a blowerbrush - not a tissue.
You are asking for a "1 size fits all" solution for your settings, and indoor and outdoor use really means different settings.  What you should be looking for is the "White Balance" setting - on Auto it will be about right, most of the time.  You should be able to switch between indoor/outdoor settings (but they may be called portrait and landscape, or similar) and you will have to look through the menus for this.