Wild swan: +1916
At CN we use two common sizes of book:
Demy (about 222 × 148 mm). This is considered a pocketable/baggable book suitable for convenience reading and so more popular for fiction. Doesn’t have much room for diagrams, pictures or charts but the narrower pages make reading prose easier.
Crown (about 195 × 252 mm). This is a larger book with more room for more complex layouts such as images with annotations. It is a little big for putting in a handbag but still pretty manageable. We selected this as it is the most popular size for reference and non-fiction.
If you are using MS Word I would recommend that you make all your changes in MS Word and upload your word document. Make sure you read through the publishing guide and watch Anna’s formatting guide videos found in the manuscript step of the publishing process before uploading your manuscript. You can also see this page for hints and tips on typesetting and formatting.