Did you know there is a new e-mail hoax going around, that says,"returned" or "unable to deliver?

Does anyone know of an up-to-date & trustworthy site is to receive weekly newsletters to warn you of the latest hoax, worms, trojans, and the like?? The only sites I've found so far, are monthly letters, and tell how to use anti-virus and update your pc. I'd like to know what's out there. I just bought my pc and I'd like to know.......any info. you can provide will be greatly admired!!