There are many, many groups of Jedi and Jediists in the world, of which TOTJO is only one. Granted, we're usually one of the more easily recognizable ones (thanks, Google!), but we don't even come close to a monopoly on the title or the philosophy.
Also, Jedi are a somewhat integrated community, in that you'll find people with multiple memberships are rather common. As such, we have quite a few people here at TOTJO who have been members of other Jedi organizations, and I'll let them answer from their own perspectives.
That said, here at TOTJO, we don't subscribe to the "light"/"dark" dichotomy in terms of teaching. We tend to view the Force as universal and mostly neutral, generally speaking, and where we use the terms "light" or "dark" we typically either use them in reference to our own, personal actions, or our own, personal motivations. They are parts of a balance scale; together, not separate. To influence one influences the other, so it makes no sense to divide them as such.
The "Light", "Dark", and "Shadow", you may have heard of could be a reference to Force Academy, as I've heard their members use those terms. They are not terms you'll find at TOTJO unless you apply them to yourself.
Almost every Jedi group will have different beliefs, definitions, and the like. Heck, almost every Jedi has different beliefs, definitions, and such, so getting any group to agree on anything is usually only done for generalizations or formality's sake.
I encourage you to poke around the FAQ and any of the materials you have access to as a guest, to question as many of our members as you would like, and to speak with the appropriate representatives for your age range and interest level here at TOTJO. They will be able to give you much better answers than I have, I think, and help you decide if you'd like to hang out with us here (in addition to anywhere else you choose to).
