What’s the most common mistake authors make before their book launches?

M.J.:  Not investing enough of the advance back into the book or investing in the wrong things.  At least once a week I get a panicked call from an author who spent her whole budget on PR and a website and now has a gorgeous page and no press.  No matter how great a publicist is you are still paying for effort.  And there’s no guarantee you will get press.  Press is about news.  Not about quality.  My rule of thumb is for every dollar you spend on PR spend $3-$5 on marketing because marketing is guaranteed.  If you split the budget and the PR works – great – you got press and marketing.  If the PR doesn’t then at least you got your ads.  As for the website – no one goes to Google and types in show me a website I’ve never seen for a book I’ve never heard of.  Your site is mostly for readers who already love you and want to see what else you’ve written.  In the beginning – simple is fine – if they’ve heard about the book and want to know more – a pic of you, a cover, an excerpt, review, buy buttons are great.  And please please before you hire anyone – get references.