The title of this book is very misleading. Originally published under the title When Friday Isn't Payday, this "21st Century" book was originally published about 15 years ago and on some fronts may have been out of date even then. Almost all the accounting advice, for instance, is about the manipulation and comparison of paper invoices and hardbound records books. There is a section on on-line marketing, but it's hopelessly out of date, suggesting that your business really should consider getting a web page and saying what an amazing new tool e-mail is.
This is a re-write of the original, but it's clearly not a major overhaul. Little comments about computerized accounting systems are tacked on the end of pages and pages about paper accounting.
Beyond technology, the amounts of money used in examples are confusing, since they are sometimes unrealistically small and sometimes seem more contemporary.
There is certainly nothing in the book that distinguishes it as a "21st Century" work. The title is just plain misleading.
That doesn't make the book at all worthless, of course, it's just disappointing. Part business manual, part self-help book, part self-promotion, it's really quite useful in many ways. It will walk you through preparing yourself emotionally and financially for what lies ahead in starting a small business. It's pretty biased toward businesses that manufacture or sell a physical product, but that's most of them, and what he says is probably true for all businesses, if you use a little imagination.
There's a lot of good stuff in here, particularly when the author reaches into his own experience for examples, but you'll probably want another book that will help more with the mechanics of how a business is run these days.
The author also goes in for a lot of religion, which is certainly his prerogative, but is a little off putting for those whose spiritual beliefs may vary from his. Toward the end of the book he even suggests that, like a twelve step program, you can only succeed in small business if you accept that God will get you through it.
Worth reading. But if you're only going to buy one small business book, look for something more up to date.