Today I'm finally getting around to wrapping up my series on web resources for cat owners with this piece on diet, nutrition, and parasite prevention.
Your Cat's Nutritional Needs - A Science-Based Guide for Pet Owners - this informational brochure is produced by the National Academy of Sciences, so you can take it to the bank.
Companion Animal Parasite Council: Information for cat owners - I agree with virtually everything they recommend provided it's tailored to local risk realities. Adult housecats eating commercial cat food and living completely indoors in my region of Southern California are essentially NOT a factor in toxocaral larva migrans problems in children, particularly when compared to puppies living outdoors in the American Southeast. And IMHO, CAPC overrates the value of fecal microscopic testing in asymptomatic animals because of the unacceptably high incidence of false negatives.
American Heartworm Society - we are not in an endemic heartworm area here in the San Fernando Valley (yet), but it is a disease of potential importance in cats from other areas where it IS endemic: Northern California, the American Southeast, and any areas with significant ongoing mosquito issues (Marina del Rey is a local pocket of trouble).