As you said thats pretty broad, what exactly do you want to know?
Don't smoke while using blackpowder
Keep black powder away from sparks and flames
Store in a dry place
Keep your black powder dry at all times
There's so much more I can get into but I have to leave now, I'll be back later to post more info about blackpowder.
If you can't find what your looking for online try looking on the internet for books about black powder shooting. You can also go to a local book store and see if they have any books about black powder guns in thier hunting and gun hobby collection. Once you read more about it and you get the gun you want read the owners manual cover to cover.
People have this idea that black powder is like dynamite. One wrong move and you'll blow yourself up. Its no more dangerous then modern gun powder. You can just as easily injure yourself with modern gun powder or have a round blow up in your face from a gun mechanical malfunction. Black powder is pretty stable. If you drop it-it isn't going to blow up. If you hit it with a hammer againg it isn't going to blow up. As long as you don't do anything stupid you'l be fine.
Don't smoke while using blackpowder
Keep black powder away from sparks and flames
Store in a dry place
Keep your black powder dry at all times
There's so much more I can get into but I have to leave now, I'll be back later to post more info about blackpowder.