This is a bit of an angry rant. I apologize for that. If you don't want to read on, here's the gist--if you haven't done it or haven't seen it done first hand, don't be giving advice! Something I've come to hate are armchair craftsmen and google/wiki scholars.
I'll confess I've been guilty of it. It was even encouraged at a hardware store I worked at. I didn't know anything about woodworking at 17, but people asked me for advice like I should know. We were supposed to know. My bad advice was responsible for more than a few returns. Thankfully no injuries.
But I think I know better now at 30.
For the purposes of this post, I'm only going to use metalworking examples.
I want to bring up some advice a former member gave here once. Now, I like this member, he's a good guy. If he's reading this, I hope he doesn't mind that i'm using him as an example. I think he would approve.
Someone once asked if titanium would survive a cone 6 kiln firing. It won't. It will probably burn. This member didn't believe that since he observed that it didn't melt until much hotter, but I've seen it happen. Google "LA Titanium fire" if you've got a strong constitution. Titanium burns before it melts.
I was 16 or 17 and was very generously given a titanium bar by someone who wanted to encourage my metalwork. I tried to forge it. Didn't really move well and cooled off almost immediately (no thermal mass). So I cranked up the blower and tried to get it to bright yellow heat. I pulled out a sparkler that wouldn't stop burning! I tried to put it out in water and that made it WORSE! I panicked, plunged the rod into my mother's garden, and ran into the house to hide. If a metalworker asks, I'll say I've never worked with titanium because I'm too embarrassed by that incident.
I know a few smiths who started up not too too long ago--about the same time I got back into the craft. They had the same typical learning curve of any ambitious young metalworkers. Learning that cutting corners doesn't make a good knife. Learning that you've got to use a centre punch if you want your drill bit to sit still. Learning about basic hammer control and technique. There's only a handful of ways to swing a hammer so that you don't ruin your arm swinging it for 8-12 hours a day, 5-7 days a week.
But at some point they started bypassing that. One started teaching classes. This put a knot in my gut. He knew the stuff in theory, but he didn't have the shop experience or self-evaluative tools to back it up. Shop practice is a big deal, for metalwork and ceramics. Things like not grinding aluminum and iron in the same go ('cause that's a recipe for thermite!). Proper ventilation (no grinders in the basement!). Proper casting safety (molten metal doesn't behave like water!). Proper chemical and scrap storage (that's how the LA titanium fire got started). This stuff doesn't come from books, it comes from knowing your materials and work environment.
Here's an example from a different person. A beginner wanted to learn to forge brass. That's fine, people do that. However, forgeable brass is hard to find, and brass has a bad tendency to off-gas zinc vapour. No good. I know people who have died from zinc poisoning. I advised that cold forging bronze would be better--heat the bronze to red heat, cool, and hammer till it gets stiff, then reheat, cool, etc. I didn't say "cold forging" though, I just thought it was clear from the context. Someone said "wait, you can't hot forge bronze, he should hot forge brass, it's easy, forges like butter. Just heat to 600C, to avoid zinc fumes, and hammer away."
This would have been good advice except for one thing--no beginner in the history of ever has a way to determine 600C. It's the same colour as room temp brass. And there are no fixed temp electric kilns or pyrometers available at the local hardware store. Tin bronze, on the other hand, doesn't have the off-gassing problems of zinc in brass, since tin doesn't boil until much much hotter. It's a very easy thing for a beginner to heat bronze to red heat, quench, and forge.
So there's my rant. I hope you see the point of it. Books and Google will only get you so far, and then they get you into trouble--or other people into trouble, if you're only using Google and books to give advice. Don't get other people into trouble, please?