Take 15% of your gross household income and start investing it into your retirement. Start with your company's (k) plan and receive the full employer match. Key Points. Dave Ramsey expects an unrealistic return on investment. Ramsey has some misguided advice about choosing investments. DAVE RAMSEY'S GUIDE TO INVESTING | 1. Seek the advice of a qualified financial advisor so you can ask questions and build a solid investment plan you can.