Get your book really ready by following these steps:
1) You need a distribution strategy (whether POD or off-set - just the logistics are different) - how sad is it to create great buzz - and you don’t have your book anyplace where the trade and consumers can get it for your anxious buyers. Big lost sales and a waste of $$ on the publicist.
2) To engage a trade distributor (assuming you are doing print runs) you must have a written marketing plan for them.
3) You have to make sure that your product is top notch - or a publicist won’t take it - their reputation is on the line with every book they recommend to their media contacts. that is what you are really paying for - who they know.
4) You have to make sure that your price is competitive with other books in your genre or no amount of publicity will create the sales that you expect.
5) You need a good media kit for the publicist to use as a basis for the publicity she/he will create for you - or you can pay the publicist to do that work for you.
When I can "have it my way" - which isn’t often (<: - I prefer to work on the book at least 6 months ahead of the pub date - you really need that much time to get the marketing/distribution/pricing plans together, apply to distributors, get their paperwork done, get their sales team representing your book to the chains, the chains place their advance orders, you know how many to print and ship to them, they have to get them in stores - all prior to your pub date.
A website is another activity that should be done as early as possible - you can use it to begin creating advance buzz for your book, have a media room where the media can learn about your book (cover art, pictures from the book, pub date, etc.) and a place to post your media coverage as it comes in. You can post your Table of contents, a sample chapter, do a blog, and so on - lots you can do to start building that platform waaayyy ahead of the book.
You also need your publicist in place with your media kit to do pre-pub reviewers 3-4 months minimum before pub date (required time), get early copies out to large magazines with long lead times, and then when the time gets closer, do newspapers, blogs, websites, and short cycle magazines.
WHEW!!! See why it takes 6 months? Oh - and YOU have to follow-up on all this to maximize the impact.
My motto: No follow-up = no results
Of course all of this is predicated on your goals for your project, the amount of resources (time & money) you can devote to your book and any constraints that your life situation imposes on you (don’t want to do live appearances or maybe radio terrifies you, etc.).
So give your book a chance – start early and plan your marketing just as carefully as you planned your words on the page.