6 Megapixel should be plenty. You should be able to go as high as 2816 x 2112. Make sure you have your camera set to the highest resolution. The Sony DSC-W30 has settings for 6, 3.2, 3, and 2 Megapixel, so make sure you're not stuck on the lowest setting. If your pictures are coming out grainy, try raising the ISO a bit.
I seem to be lacking the resolution in my images for the requirement.
They are just so grainy. I'm using a tripod, but I don't see a crisp edge in most of my pics. Is it the light?