Benazir's Hey Arnold! Webpage: Fan site includes character biographies and pictures.
Hey Arnold!: A Hey Arnold fan site featuring a comprehensive episode guide and several links.
Hey Arnold! at Nick.com: Official site with episode descriptions, sounds, pictures, and character bios.
Hey! Arnold Stuff: A site with photos of the Nickelodeon animation studio and the "Hey Arnold" cast. Artwork too.
Nothing But Helga!: Shrine to Helga Pataki from Nickelodeons "Hey Arnold!".