You might try:
The U10 doesn't offer much in the way of manual control, but my experience with the U20 so far has shown that the auto selected setting produce quit satisfactory results in both color rendition and image crispness.
My best advice to you is to experiment with camera to subject distance, play with the scene modes, force flash off (or on) and just shoot, shoot, shoot.
You must learn to work within the limitations of the camera. From what I have read, most folks have not found difficulty getting good shots outdoors in 'daylight' conditions, so I'll assume that your problems have been primarily in low light (indoors with flash).
The flash is good for only about 1-1.5 meter lens to subject distance in low light situation. If you are having focus problems in low light, try setting the focus manually (1 M) then make sure to position yourself at that distance from the subject. In low light, the camera will stop the lens wide open (f2.8) so the depth of field will be quite shallow at the 1 M distance.
The U20 (and presumably the U10 as well) will take reasonablly good 'available light' pictures without flash indoors with nomal (enough light to read by) tungsten illumination. I haven't shot under fluorescent light conditions yet. The auto white balance works quite good under these conditions if the scene has sufficient tonal range. The U20 (U10) will typically boost the ISO sensitivity to 360 under these conditions so you will experience some detector noise in the image which is typical of most digital cameras.