That's about where the guide goes all wrong IMO. The first thing is figuring out what you're using the camera for and what kind of features you'll need to do your photography. Then go find the cameras & systems which fill those needs.This guide will focus mostly on digital SLR cameras and their accessories. First and foremost, before you do anything else, you need to decide on what brand of camera you want to buy. Everything else, from lighting to lenses, stems from this one basic choice.
For instance I need a relatively small camera that I can carry anywhere which means all DSLRs are out of the picture, there's no way I'm packing a camera & lens in a big bulky bag when I'm biking hours into the woods in the middle of nowhere. I need a decently fast lens for action photography in less than ideal lighting conditions so all compacts are out. That leaves cameras such as the Olympus E-P1 and various Leicas if I go the digital route. Since I also need a built-in optical viewfinder that leaves the Leicas, and I can't justify that kinda coin since I'm not that serious of a photographer.
If I stick with film I can use my Olympus Pen FT or Chinon 35FS rangefinder. I can stuff either one straight in my backpack or even in a back pocket in the case of the Chinon. This is what I continue to do for a fair number of my biking pictures.
On the other hand if I'm just going to be doing photos at the air show every year then I don't need to worry about bulk or weight as long as I can carry it for 5 miles along a flat paved bicyle path. All I need is a big telephoto lens and nice fast focus with minimal shutter lag.