Scott Pack is something of a publishing legend. Once described by The Observer as ‘the most powerful man in book publishing’, he is the former head buyer of Waterstones who went on to be a senior publisher at HarperCollins and an associate editor at Unbound.

Nowadays he is the editor-at-large at Eye & Lightning Books, as well as a university lecturer, a prolific freelance editor and and an even more prolific tweeter to his nearly 30,000 Twitter followers.

He also delivers highly successful Guardian masterclasses on writing, on which Tips from a Publisher is based. From a handy introduction to how the publishing world works and how authors fit into it, to practical tips on writing your book and strategies for editing and re-writing, this new book is an indispensable guide for authors.

It's out on 2 January, but if you pre-order your copy before midnight on 31 December, Scott will provide a free assessment of a 1000-word sample of your manuscript or check over your query letter. To qualify, follow the link and enter the code TIPS in the discount box right at the end of the checkout procedure.