Winner for best cloud-sourced myth(s):
It don't mater how bad you're speling or grammer is, or how illegibly formatted your submission. As long as you have an idea that's the new Harry Potter or DaVinci Code, publishers will send your book to a ghost writer to be written, slap a celebrity's name on it as "author", and give you all the money. Or none of the money.
Alternatively: it doesn't matter how unsalable your idea is if your writing is limpidly beautiful and lyrically whatever. It's only about Art. Who cares how many books we can sell?
Alternatively again: it doesn't matter how beautiful your writing is, because it's only about money. Publishers are actively rejecting most slush manuscripts as "too good" and only publishing cliche-ridden drivel because that's the only thing that sells.
Only the young and vivacious get published. Publishing isn't just a popularity contest in terms of your manuscript, we're also looking ahead to the interviews you'll have to do in a bikini. So wax now.
You must get rejected 26 times. L'Engle, Seuss, Grisham, Karen Jay Fowler... all the best writers have been rejected exactly 26 times. (No doubt this number is because of some secret cabal in publishing.) If you get a 27th rejection, though, it means you're crap.
Once you are published, it's easy-peasy to get all your friends, family members, and crit group partners published, too. Once you're in the secret club, you can recommend up to 26 new members per month. (No, of course your editor won't mind the influx of recommended manuscripts--she's doesn't have to read them, just put them on the secret order's altar and read the secret fortunetelling bones over them.)
Moreover, this is really the only way to be published, since publishing houses go to any lengths to avoid reading submissions. This includes giving false addresses (ha, Candlewick is located in "Boston"! Honestly, who would fall for that?) and simply moving away from old buildings once they become heavily impacted with piles of slush.
Finally, if you earn out your advance and make your publisher glad they worked with you, you clearly didn't get paid enough. Fire your agent, so that at least someone will have learned their lesson.
Thanks to Sam, Chris, Merry, Tricia, Literaticat, Carol, Michael, Vonna, Hope, and A.L.!
P.S.: Anonymous, the secret society of bloggers (led by Nathan Bransford and Literaticat) is factual. This was a MYTHS contest.