I bought "The Ultimate Small Business Guide" and it was a very useful book during my first year in business. Lots of ideas, things I might have overlooked, detail-oriented stuff.
I have an MBA also. I found it was more of a bigger picture degree. Yes, you learn about accounting, finance, economices, marketing, and mgmt... but nothing about sitting down and running your own thing (although that class was offerred).
IMO, the biggest advantage of the MBA was seeing sustainable competitive advantages. Three years afer graduation, I still walk into any room and automatically just smell a few opportunities. I talk to someone about their job - they can be a roofer, signmaker, mechanic - and my mind automatically makes connections for opportunities I can find in introducing them to someone, or some joint project.
It teaches you to smell opportunities, simply put.