It seems to me that when it comes to the specialized skills like brazing you can't possibly learn how to do it just from threads on a site like this - even if you had seen all the threads on the old site you'd still need to look at tutorials specifically about brazing or get a book like The Complete Metalsmith, and in those tutorials/books you'll find the info on safety (I looked at dozens of YouTube tuts on brazing). Plus of course when you buy the materials there are usually labels explaining safety precautions.
I'll just quickly throw out a few of my own safety procedures here -
For my brazing station I use a fume extractor made by Xytronic - it's a small device with a built-in fan and it holds filters - you place it as close as possible to where you're brazing - needs to be within 6 inches (which can be difficult) and it sucks in the fumes and filters them - you can also rig it up to the end of a dryer hose running outside if you want to completely remove them.
I also wear gloves with reinforced leather fingertips (the standard welder's gauntlet type you find super cheap at hardware stores) and a clear plastic face shield that hinges up or down like a welder's facemask but it's clear - like what you see the riot police wearing. I also wear safety goggles under the facemask - might be overkill, but better safe than sorry. Also a thick denim apron to protect my clothes. These are all available at any decent hardware store pretty cheap.
^^ This is also the same getup I wear for cutting or drilling metal.
One important piece of safety equipment is disposable nitrile gloves. They're far more resistant to certain chemicals than latex - in particular epoxies. Always wear nitrile gloves when working with epoxy putty - it's very toxic stuff (they don't tell you that on the label and always show people working with it bare-handed).
That's all I can think of at the moment - of course I don't work with toxic liquids through a sprayer like when painting silicone and such - for that you need a solvent-rated respirator and some kind of aggressive ventilation system. They always say opening a window and putting a fan in it isn't enough, but for many of us it's the closest we have to a built-in spraybooth. I've learned one important fact - the best 'windows-based' method is to open 2 windows across from each other and put a fan in one sucking air out. The windows should be directly across from each other or as nearly as possible - it doesn't work going around a corner (I mean there needs to be a direct line-of-sight between the windows). You can test it first with some cigarette smoke or a candle or something.
For drilling I've never heard you should wear a respirator - for cutting metal either. Just good face and eye protection and cover your clothes unless you're wearing old raggedy stuff. Somebody who knows better might correct me on this though.
Thanks for the info. I'll watch some more tuts and pick up a book on metal work.