Well, I've got to say, Guerilla Marketing by Jay Conrad Levinson, is every entreprenuers bible. It discusses marketing at the grass roots level, and offers practical tips that actually work!
It's one of those books that ought to be read with a notepad and pencil close by, as it's chocka block full of ideas, and strategies. Like the 16 secrets of Guerilla marketing, and consent selling, committment, and how long to hold out marketing. When to stop a "marketing attack"
It's the book written for the small fish, with the bite sized budget!! I rate it 5 Stars!
Oh and the best part, as far as books go, it's VERY cheap at amazon!!