In addition to all the stuff you read on the internet, which can be at times zealotic, biased, untrue, technically anal and overbearing I'd suggest that you go down to your local camera store and ask to try competing models from the manufacturers you already suggested.
At least the three names you suggested are all "true" camera manufacturers, as opposed to electronics manufacturers who want a piece of the digital camera market. (sony etc.). All three (canon, nikon, olympus) made cameras before the digital age. This is important in a few key ways:
1. It means the camera will be well thought-out, and user-centric
2. The experience of taking photos will be easy and fun
3. The optical components will be a good quality
4. The design will be basic, in a solid, easy-to-use sort of way.
The reason I say to go and actually try the cameras (apart from the reason I said above about reading things on the internet) is that all three manufacturers will have models with equivalent features. This is where the look and feel of the camera comes into play. You may hold one, and for some intangible reason, just like it more. It may fit your hand better, or feel more solid, or may have a better menu system (or one you can understand better anyway!). You may like the weight of it or any other of 1000 reasons that you'll never get from simply reading about things on the internet. Also, camera shop owners tend to know A LOT about cameras! Even if you don't buy there it's a good first or second step.
My steps:
1. Read a little on the internet to know what models you are looking at, etc.
2. Go to a camera shop and get to grips with the models you are interested in.
3. Take your time, use the menus in the shop, carefully examine which features will be most useful to you (in a real way).
4. Buy on-line for the best price, or in the local store if you want to build a relationship with local trade. (A friendly local camera shop can be very useful indeed especially with returns etc.)
Good luck!
P.S. - From my experience with the nikon D70 I'm buying Nikon all the way from now on - they are making great cameras (and lenses) right now. - However, that is not to say that Canon or Olympus are not also making great cameras. I went shopping for a EOS 300D and came back with a D70, a couple of 100 $ more, but the "look & feel" of it struck me over the head. It was more solid, a better design, and when I got it home and had a chance to play, had many more features than the older 300D. That is why from now on, I ALWAYS recommend that people go to a camera shop when buying any camera - it's really amazing how big a part the intangible aspects of a camera can have on how much you enjoy using it - and therefore on how much you will use it! Again, good luck.
