The Internet! It's on computers and it's not just for pornography anymore! There's plenty of metal swirling in the cesspool known as the World Wide Web. Consider these sites a good place to start.
News
http://www.bravewords.com - Canada's Brave Words & Bloody Knuckles ("the CNN of Heavy Metal")
http://www.blabbermouth.net - Metal news, reviews, and commentary (owned by Roadrunner Records)
http://deathmetal.org - Death Metal Underground, net’s oldest and longest-running metal site.
http://www.metalhammer.co.uk - British Magazine Metal Hammer
http://www.metalunderground.com/ - Metal Underground "Some music was meant to stay underground."
http://www.talkingmetal.com - Talking Metal Podcast
http://www.metalcallout.com/ - Heavy Metal Callout
Radio
http://www.accuradio.com - featuring seven streaming metal chanels
http://www.hardradio.com - “The World’s First .com Internet Only Radio Station Online Since 1995”
Labels
http://www.centurymedia.com/ - Century Media
http://www.metalblade.com/ - Metal Blade Records
http://www.nuclearblast.de/en/ - Nuclear Blast
http://www.roadrunnerrecords.com/ - Roadrunner Records
http://www.sanctuaryrecords.com/ - Sanctuary Records Group
http://www.spitfirerecords.com/ - Spitfire Records
For a full listing of Heavy Metal record labels, visit Wikipedia.
Other Links
http://www.martinpopoff.com/ - Martin Popoff's Official Site - Martin wrote the book on metal...literally!
http://research.google.com/bigpicture/music/#METAL - Google Metal Music Timeline - A visual representation of Metal's popularity over time.
http://www.metalseason.com/ - Metal Season - Hard-to-find new European releases on CD/DVD. Highly recommended!
http://www.metal-archives.com - Encyclopedia Metallum - The heavy metal encyclopedia
http://www.brutalmetal.com - Metal Discography Reference
http://www.rockdetector.com/ - Rockdetector - "The World's Biggest Rock Resource on the Web."
http://www.truemetal.org/ - Listing of Metal Sites
http://www.heavymetalcomedy.com/ - Heavy Metal Comedy - Metal is funny, like, ha-ha funny!