The USDA APHIS brochure titled "Backyard Biosecurity Practices to Keep Your Birds Healthy" is a good resource for general information on preventing poultry disease.  The brochure can be downloaded as a PDF for printing or you can order a supply from the website at http://www.aphis.usda.gov/vs/birdbiosecurity/brochures.html

Here are links to the Public Health--Seattle & King County website on avian influenza at http://www.metrokc.gov/health/prevcont/pandemic-flu.htm and the WA State Department of Agriculture's site at  http://agr.wa.gov/FoodAnimal/AnimalHealth/Diseases/AvianInfluenza/default.htm    These websites will be updated as new information becomes available.