With 10 mil after taxes you would be able to make between 400k and 800k a year without entering the stockmarket.
The absolute safest investment that you have at your fingertips is the US Treasury. They will also provide you with the lowest rate of return.
The next safest ave. that you have in the US is Tax Free Municipal Bonds and/or Pass Thru Securities. Now mind you that you would want BBB or higher as that is considered investment grade. The higher the rating the lower the rate and the greater the level of safety.
If you decide you want a bit of a higher rate you can always invest in Corporate Debt but make sure that you are investing with a company that has a PROVEN track record. GE and the like are the safest players in town.
There are also REITs (Real Estate Investment Trusts). Do be careful when looking into those however. Some are fantastic investments while others are shakey at best. There are REITS that are private (no market risk) and public which are on the stock market and do carry market risk (volatile).
You can always look into CD's but remember that 100K is the limit (per bank) for the insurance from the FDIC. You can always invest more but god forbid the bank goes south you are SOL for anything over the FDIC coverage.
Banks do typically invest your CD money into Collateralized Mortgage Obligations. This is where you can kick out the middle man and get the banks rate as opposed to the Investors rate. GNMA, FNMA, and FHLMC are three of the biggest companies. GNMA is the only direct oblgation of the US Govt. Meaning that if the investment goes belly up the Govt. will step in and take care of the repayment of principal. One again you need to be aware of the Credit Rating of the issuer. AAA is the way to go.
Now if you are looking for growth and income at the same time there are plenty of stocks and mutual funds out there that will potentially help you accomplish both. I have seen stocks that pay dividends as high as 20%. Keep in mind that when a stock is paying those kinds of dividends they are typically VERY volatile.
There are a wide variety of investment choices out there for you. What you should do is meet with a financial planner/advisor and review what it is you are looking to accomplish.
Never put all of you eggs into one basket however. You should always have a well diversified portfolio. Now I am not saying that you should invest in 40 different companies or instruments but you should have exposure to several different sectors of the market.
Make sure that you do your own due diligence on this. Noone knows better than you what it is you are looking to accomplish with your assets.
I hope that this helps in assisting you with your future decisions.