This is a very useful guide on how to write and sell your romance novel. Valerie Parv has written and published 31 novels, the majority of which were published by Mills and Boon. She uses extracts of her own writing to show what works and why, and covers areas such as writing dialogue, choosing settings, creating believable characters, changing viewpoints, and exactly how much detail is too much.
There is also plenty of advice on how to adhere to the writer's guidelines or 'tip sheets' sent out by publishers: How to do a word count (did you know that computer word counts can be too accurate? You could cut out up to 20% of your novel unnecessarily!). How to send a sample synopsis, a query letter, and how to write an art brief for the cover picture of your novel... Basically, how to market your book.
The publishing houses listed are mostly American or Australian (Parv lives in Sydney), and the small area that talks about incomes and advances refers to dollars. Still, if you want to find U.K. publishers, just buy The Writers Handbook!
The only thing I would say as a caution, is that Parv uses her experience of what is an acceptable plot, novel length, viewpoint, etc. as recommended by Mills and Boon. If you are considering writing romance that would be more suited to another publishing house, this book will probably be a lot less useful. Having said that, Mills and Boon are the world's largest publishers of the genre, so if this book teaches you how to be one of their writers - that can't be bad, can it?