My all-time favorite investing book? It might be One Up on Wall Street. It's full of investment wisdom. Here are the 10 most valuable lessons from this classic:

1. Stay within your circle of competence Only invest in what you understand

3. Let your winners run You only need a few big winners during your investment career

4. Everyone has the brainpower to make money in stocks KISS: Keep It Simple, Stupid

5. You are an owner As an investor, you are the owner of the companies you invest in

6. Focus on the fundamentals Nobody can predict interest rates, the future direction of the economy, or the movement of foreign currencies

7. Buy healthy companies The biggest losses in stocks come from companies with poor balance sheets

8. Accept periodic losses Every investment contains risk. Never let temporary setbacks discourage you

9. Use common sense Focus on the big picture and keep it simple

10. Don’t try to time the market Time in the market beats timing the market