Hey, missed this post before.
I can give you the short version of it right now:
The site is the successor to Webintosh, founded by Dan Hughes in January of 1997. 18 months later, he was burned out, and sold the site to me. I brought in Dave Hamilton as a business partner, and we changed the name to The Mac Observer on December 28th, 1998.
It’s through Dave’s gift in business management that we managed to hang in during the tech bust of 1999, and though I tend get most of the credit from the public for TMO because of the content, we not only wouldn’t be what we are today without him, we wouldn’t be here at all if it were not for his hard work behind the scenes.
Our first Assistant Editor was Kyle D’Addario, but Apple stole him as one of the first Mac Geniuses when the Crossgates Apple Store was opened. I am still bitter about that… 
I don’t have the exact dates in front of me, but we’ve had a variety of very talented writers writing for us throughout the years, including (but not limited to) Bob LeVitus, Ted Landau, Andy Ihnatko, Rodney O. Lain, Nancy Carroll Gravley, Vern Seward, John F. Braun, The Idiots (Gary Randazzo and Randy Soare), Wes George, John Kheit, Eolake Stobblehouse, Mike Washlesky, Jon Simon, Bill Troop, Tim Hillman, Todd Stauffer, Michael Munger, Owen Linzmayer, Arlen Britton, and a host of other folks who have written some great editorials for us.
In 2003, we decided to make an investment into more traditional journalism, and we brought Brad Gibson on board. He eventually became News Director for the site, and helped us revamp the way we handle news. Brad has left to pursue other opportunities (not a euphemism), but still contributes articles to the site today.
It was 2003 when Misha Sakellaropoulo joined us, too. He has had a variety of roles with us (substitute editor, news editor, reporter, trade show god, and several others), but his most recent role has been in developing and managing the reviews at iPodObserver. He’s been doing a great job of that, and is a hugely important part of our team.
In 2005, Brad Cook came on as Afternoon Editor, and Jeff Gamet signed on as Morning Editor in November of 2005. That gives us the strongest team we’ve ever had.
Of course, it would be foolish of me to omit The Evil Girls of TMOâ„¢, one of whom is my lovely girflriend! Raena Armitage (not my GF) and Darla Sasaki (GF) have both been instrumental in the growth of TMO at various stages, and have written for us, offered advice and story ideas, and been amazingly supportive through the years (each in their own ways, of course).
Indeed, I met Darla through these very forums, and the four years+ since then have been the best years of my life. 
Also, Raena designed the current iteration of TMO’s design!
Also, Gavin Mahan, Dan Miller, Robert Leitao, Stephen Swift, Michael Mendelson, Nick DiPiero, Brian Wheels, and several others have contributed to the site and community in a variety of ways.
It was 2003 when we had the opportunity to launch DealsOnTheWeb.com , differentiating our product offering greatly.
In late 2004/early 2005, we decided it was time to launch our own iPod site, and we set about the multi-month process of putting a news site together. We launched iPodObserver in late May of that year, and haven’t looked back. iPO has allowed me to express my musical geek to some extent (and w00t! for GarageBand!), and I am quite proud with what we have done with it.
Our forums were launched in…1998? I forget now. Actually, it was probably 1999, or early 2000. We had forums before that, but they were an UGLY mess. Because of that, I spent a couple of months hanging out in other forums trying to find out what it was that made forums successful. I don’t know that I found that formula, but I did discover what it was that I liked about forums, and more specifically, what it was I didn’t like.
Accordingly, I set about to build a forum community that would be the kind of place where I wanted to hang out. Fortunately, we had some great people adopt us from the beginning, people who shared some of the ideas I had about a good forum community. They helped me set the kind of environment we all wanted, and the results have been spectacular, IMNHO. I think we have the best forum in the Mac world, though it’s hardly the biggest (not even close). We have the smartest people and some of the smartest conversation anywhere.
On the ad side, we started off selling our own ads, which led to the formation of BackBeat Media (I helped found the company, but sold my interest back to other principals early on). BackBeat has since grown to be one of the most respected ad companies on the Internet, and the largest in the Mac Web. BBM has been a big part of our success in recent years.
I am sure I have left out some important folks, a definite omission on my part, and not a slight. TMO has been built with the help of many, many talented and good people, all of whom have contributed to our success in one way or another. If I did leave out any names, post them here, or let me know!
Oh, and I realize that wasn’t really the short version. 
[Edited to include Misha Sakellaropoulo’s info - Bryan]
[Edited to include The Evil Girls of TMOâ„¢ (doh!), and several other great people - Bryan]