You're sort of going to have to help yourself. Unless you had already put all of your photos in some logical order for yourself, you're up a creek without a paddle, as they say. iPhoto puts things in its own nonsensical order, so that it can maintain its database structure. Outside of that database, the folders themselves will look like a total mess in Finder. In order to see this for yourself, right click on the iPhoto library file, and choose "show package contents".
Adobe bridge, relies on the user to have maintained some semblance of order, as it is a true file browser, and does not rely on a database structure. In a way, this has its downside, unless the user is very specific about their folder structure/hierarchy.
How many photos have you amassed ? Perhaps it's not too late to start organizing from within Finder. Personally speaking, I'd NEVER rely solely on a database type program to organize anything for me, no matter what provisions were available. I use Lightroom 3, and though I do take advantage of its keyword and tagging capabilities, along with the power to make dedicated smart collections and such, I also have a method to my main file structure, and for very good reason.
This method of mine, is one of personal preference, and some may do the same as I do, but there is no one set way overall.
If you were looking for an "easy" way out, such as importing photos from iPhoto, I don't think there is a really good way to do this, since as I've said... iPhoto creates "versions" of all your photos and puts them into the most ridiculous type of folder/file order.
There is one method to use if you're really lazy... Open terminal then copy and past this command: (someone who knows terminal commands very well please confirm that I have this right)
Code:
cp -r "Pictures/iPhoto\ Library/Originals/" Pictures/
This will basically copy all of the original files from iPhoto and make them independent from its database or library file. You can then direct Bridge to them.
I would however, do as I suggested and come up with a folder hierarchy, so that future files have a place to dwell, and aren't just lumped into one folder.
I can give you ideas about that, but I'm sure you know what I'm saying and won't have a problem making up your own mind about said structure.
Doug
Edit: After you've gotten everything into folders and are using Bridge, you should delete that iPhoto library file if you had ever used it previously. It's likely a big file and you really won't need it if you never plan on using iPhoto.