ARRL (http://www.arrl.org): The American Radio Relay League
, or ARRL, is the national association for amateur radio. On this site, information can be found regarding education/training, membership, and how to get involved.
Philadelphia ARES (http://www.harcnet.org/aresindex): Philadelphia ARES (Amateur Radio Emergency Service) is dedicated to serving the community with up-to-date when disaster strikes and to build a relationship with amateur radios from other counties. Membership and training is available for those interested in joining the ARES of Philadelphia.
Ham Universe (http://www.hamuniverse.com): For all of you amateur radio needs, visit HamUniverse.com. Here you will find information regarding ham products, license studying, the different components of this high-tech hobby.