Just this morning from the communications headquarters I call my shack, I was able to check propagation, read real-world reviews of a piece of gear I'm interested in, inform a fellow ham that I had received a misdirected QSL that was due him and send a signal report to the operator of a 10-meter beacon -- and that's just for starters. Seems like the Internet's much vaunted threat to amateur radio has become, in reality, a boon. The 'Net has, through the mostly individual efforts of thousands of hams worldwide, matured into an almost inexhaustible resource.
I have a pretty extensive ham radio reference library with books on antennas, homebrewing, electronic theory, rules and regulations, DX'ing; you name it, I've probably a tome on the topic. But amateur radio is too big for anyone's personal book collection to cover comprehensively. And what about time sensitive activities like contests, regulatory announcements, hamfests, club meetings and conventions? Where else can you find, at your fingertips, the schematic diagram for a 60-year-old Hallicrafters receiver, or the QSL manager for that ZL8 you just worked? Shopping for a new, or used, piece of gear? It's all just a dial-up away on your favorite ISP.
In addition to the multitude of valuable services and site listings offered by eham.com, there are hundreds of "jump" sites catering to your personal ham radio interests. Having a problem with your rig? Housing covenants and antenna restrictions got you down? Can't find that octal socket for your "hollow-state" construction project? There's a myriad of mailing lists providing forums (and answers) on radio interests from the pedestrian to the arcane.
In the five years I've had Internet access, I've been hamming more, joined more special interest groups and clubs, and contributed more to the hobby than I have in my previous 20 years as a ham. Who knows, the Internet may prove to be just the "kick start" ham radio's needed (and we've been endlessly debating) for years.