The Ten Crack Commandments by Biggie Smalls provides solid basic advice in business and finance.

Even more relevant if you sell physical products. When you ignore the filthy language and break down the lyrics into business speak, there's a lot of gems. This is how I interpret them:

Intro

I've spent nearly eight years in product design, and the years have seasoned me into a driven professional. There are tried and true rules I've observed that will help you avoid obstacles and propel your career forward.

The Commandments, Interpreted

1. Don't gloat about success or divulge sensitive information. Those with nefarious or desperate intentions would be able to take advantage of you.
2. Keep your cards close to the vest. Sharing too much strategy opens opportunities for competitors to gain an edge. Make strategic moves swiftly.
3. Maintain solid boundaries.
4. Never misuse business funds or dip into the budget for personal matters.
5. Maintain a healthy work-life balance.
6. Don't take somebody's word for it, especially in matters of future cash flow or protections. Signatures and checks required and required upfront.
7. Mixing family and business can be tricky. Homophobia is always bad, though.
8. Keep inventory safe. Keep assets protected.
9. Mind your own business. Focus on yourself and your success.
10. Know your limitations, strengths, and when to gather more education or experience. Don't get over your skis.