How to post-process noisy images?

This image is from our old FZ18 at ISO 100 (!) but my new F770 has similar problems with images at ISO 800 and above. The image looks OK from a distance, but the dog's fur is mottled and does not show any hair detail, and the cat's fur is a noisy mess.

Obviously I will downsample this.

Does anybody have pointers as to an optimum approach? Noise reduction, how? Post-capture sharpening? Bicubic sharper or bicubic then smart sharpening? Thanks.