First Time Purchases

I'm going to buy a bike for the first time, to have some fun and exercise, but I know nothing about bikes. I expect to spend in the $600 range, and I expect to have the bike for years, so I'm trying to make sure I get the best machine possible.

For me, this isn't like when I built my first computer: I had been using computers of all sorts for years, and had a pretty good idea of what I wanted out of the machine. The high end pre-built computer sites at the time, enthusiast sites, and computer mags were pretty useful for specing out parts for computers of all sorts of price points, and there were lots of options in the same price ranges for every part, with pretty much equal capability. Because of that, I think I felt like I couldn't go too wrong with any individual purchase.

With this bike thing, the only mags I could find all seemed like high end enthusiast mags, for BMX and road racing. In a buying guide of the latter, it had a section of 'great deals for $1000.' Ha! No. I've been to a couple bike stores so far, and have tried four bikes of different types, but I'm still not sure. It is definitely not a wide enough selection to get a general concept of "bike-ness", so I need to try more brands, and types; though, I'm leaning toward a hybrid, and cyclocross sounds interesting.

It's a headache for me, having to do so much comparison shopping and research... in person. The Internet makes so much so very easy, but with this purchase, there is so much biased, and poorly thought out opinion, I am convinced it should not be this hard to settle on, or be enthusiastic about a bike, yet it is a pain.