Passive Guy goes over the non-compete clause in a contract an author sent into him. Here is part of his analysis:
PG thinks a reasonable interpretation of authorize publication would prevent the author from signing a publishing contract and receiving an advance for an entirely unrelated book until six months after publication of the first.
So, even if you’re writing up a storm, either make that advance last or go back to being a barista until you’re free to sell another book.
Passive Guy makes contracts interesting, I would encourage anyone interested to read his blog post.