I went to the above 3 hour workshop on 16 October 2009. As I have recently obtained a copy of Alison's useful 'Marketing Your Book', I originally booked for a workshop with Jo Herbert, editor of the Writers' and Artists' Yearbook, in order to get a different perspective. However, Jo was unable to attend and Alison Baverstock's stepped in. Alison knows the publication industry better than anyone else I've come across and was generous with her advice on how to pitch one's book at agents and publishers.
She pointed out that for an agent or publisher, both the book and the author are important, Both have to be promotable and interesting. Their decision on a book will depend on their view of the potential prospects for it.
She stressed that the manuscript must come first. It must be good enough or everything else an author does is a waste of time. It is important to make a good first impression, you only get one chance. Therefore, don't rush into things.
Ensure your approach to an agent is well considered. Try a little flattery but don't grovel, suggest which genre your book fits but don't tell them - they are the experts.
If a publisher's details say no unsolicited manuscripts, it is worth writing them a letter asking for the name of the commissioning editor. Then a letter to this august person may result in your manuscript being solicited. It still might not be published though.
Be polite and never slag off agents or publishers to others in the industry. It is a close industry in which everyone knows everyone else.
Make each approach personal and specific and don't try too many at once. It is permissible to write that you would like to know what they think within -say- 6 weeks or 2 months. Keep track of who you approach.
In letters, aim to be succinct but incorporate hints that you are interesting and quirky. Don't give you age away unless it is relevant.
Authors nowadays have to have an author's platform. That is a presence on the internet, such as a website, a blog, a twitter stream and a facebook page. Authors have to be open but Alison warned about putting anything onto the net that you might regret later.