These are definitely my favorite software marketing books, and all are related to the marketing, sales, strategy, or the business of software. Most are fairly recent but I've kept one or two oldies but goodies - like "Crossing the Chasm" - because I think there's still a lot to be learnt from them. Please note that some of the links below are affiliate links, and at no additional cost to you, I will earn a commission if you decide to make a purchase after clicking through the link.
As time allows, I'll add my reviews/comments to each of these... but for now here's the list and the links, with those that I've reviewed listed below.
The Ultimate Marketing Toolkit by Paula Peters. This book provides a lot of useful tips, from do-it-yourself marketing, step-by-step instructions for creating your business cards, a professional bio, letters, brochures, press releases, ads, web site content to newsletters.