Of all the books and research we've read, these are the ones we've found the most useful information from and influenced a large part of our redesign at Wufoo :
Landing Page Optimization
http://landingpageoptimizationbook.com/
(best technical book on how to measure landing pages, do not buy SEO books, they're all terrible and rehash what you see on most blogs)
Word of Mouth Marketing
http://wordofmouthbook.com/
(sometimes great marketing has nothing to do with what you do on the web)
Made to Stick
http://www.madetostick.com/
(just a great read on how you should shape your copy and ideas so they have maximum sticking power)
Whoah! You realise you are referring to yourself as 'we'? You realise that you are losing your voice as an individual, and taking on a more neutral tone that represents a company? You realise what is happening, right? Your company is no longer a collection of startup founders, it's just a polite 'we'.
Lose that, it's the new world. Companies are made up of vocal intelligent people, not neutral hollow 'we's.
If you look at his profile he gives his real name and his company and he clearly stands behind and owns his comments. You seem to be pushing "Cluetrain" as some form of political correctness. At some point a company becomes more than a collection of startup founders, which it must to succeed, and makes commitments as a firm based on a working consensus. I don't find it hard to believe that the founders talked over what books had been most useful: for me the "we" sounds natural now hollow.
A start would be any second-year business degree marketing course textbook which discusses MASH analysis, among other foundational aspects of marketing.
You wouldn't learn the basics of programming from a 'design patterns' book, right? I'd suggest learning the basics of marketing from a text which focuses on the basics of marketing (not advertising -- that's different). The other trendy "how to synergize your paradigms to leverage the new economy's zeitgeist" stuff can be picked up later.
Ogilvy on Advertising is one of my absolute favorites, and I go back to it regularly. It's also a beautiful book with lots of large photos of campaigns. It's not specifically "marketing" of course, but it covers that area, as well.
The funny thing is that a lot of folks in the business writing books today like to present themselves as being innovators and mavericks going against the "old school" of advertising and marketing...but Ogilvy covers a lot of the "new" techniques that folks like Godin and Ries and many others in the web era are pushing. Stuff like directly talking to your customer; the power of personal messages, for example, is covered in great detail in Ogilvy's book. Sure, the technology wasn't there yet to tweet and blog, but the ideas translate quite clearly and easily if you just think about it for a minute.
Another "old timer" (who also considered himself a maverick fighting the Ogilvy ways) is George Lois. His book "What's the Big Idea?" is full of great stories of reaching a market on the cheap.
Ries and Trout are excellent. I've read several of their books, and they all basically amount to the same ideas presented in Positioning, but they include a lot of great anecdotes that make things concrete--sometimes it's hard to see the right positioning for your products, so it can help to hear stories of how they found the right positioning for various products.
If any book results in me becoming a multi-millionaire, I'm thinking it'll be Ready, Fire Aim by Michael Masterson. Written by someone with waist-deep experience in multi million dollar revenue businesses and full of crazy amounts of advice. The focus of the book is marketing, although it most certainly crosses over into entrepreneurship a long way.
The reviews on that Amazon page should show how well it's regarded.
The thing about many "clever" marketing books, such as Seth Godin's (which ARE good), is that they don't help you clarify if what you're building is actually WORTH marketing. Ready, Fire, Aim looks at that side a lot more. You need to work out WHAT your product quite is before marketing it.
Here's a corresponding YC link from today titled, "The best Web sites and books about advertising": http://www.slate.com/id/2191446/. It's from slate.com so I doubt there's anything useful though :)
I'm saving this as I'd like to see what others recommend as well.
Wait - so instead of spending $11.99 on a book that tells you what to do, you advocate spending tons of money and losing tons of sales while you reinvent the wheel? Come on, man...
Call to Action http://www.calltoactionbook.com/ (how to think about landing pages and navigation)
Landing Page Optimization http://landingpageoptimizationbook.com/ (best technical book on how to measure landing pages, do not buy SEO books, they're all terrible and rehash what you see on most blogs)
Word of Mouth Marketing http://wordofmouthbook.com/ (sometimes great marketing has nothing to do with what you do on the web)
Made to Stick http://www.madetostick.com/ (just a great read on how you should shape your copy and ideas so they have maximum sticking power)