The Foundation Bible of starting an MSP: Managed Services in a Month by Karl Palachuk Amazon Link
I'll also throw a vote in for Traction as a general business book.
The only book that I've read (currently reading) is Managed services in a month, haven't got to the part where they (if they) talk about that stuff. You're well established so I'm not sure if it would help you.
Still a GREAT book! Here's the link:https://www.amazon.com/Managed-Services-Month-Successful-Business/dp/0981997856/ref=sr_1_1?s=books&ie=UTF8&qid=1473283679&sr=1-1&keywords=managed+services+in+a+month
Here ya go... http://www.managedservicesinamonth.com/
Buy the book on Amazon here. It's a quick read but you'll refer back to it over and over. It's a good starting point for those just getting into the game.
This. https://www.amazon.com/Managed-Services-Month-Successful-Business/dp/0981997856
Well i got the audiobook and listened to it on the way to work
IS the MSP in 30 days this book? http://www.amazon.com/Managed-Services-Month-Successful-Business/dp/0981997856 ??
Read managed services in a month. A client who doesn't understand the value of IT shouldn't be your client
http://www.amazon.com/Managed-Services-Month-Successful-Business/dp/0981997856