If the money was in cash, I'd say to do nothing for about 6 months until the "hype" of the situation died down. Since the majority of it is in one stock, you're exposed to a huge risk. Moving to gold or another single stock is not smart. Also, DON'T go to Edward Jones, Merrill Lynch, etc. If you seek out a financial advisor, go to a fee-only advisor; the others are paid on commission and will try to sell you products, what you need is investment advice, not a salesman.
As Apex Chase mentioned, a well diversified portfolio of low cost index funds is the proven method to long term wealth. If you were say, 30 years old, and invested $500k in an age-appropriate low cost portfolio, you'd have just over $4MM by the age of 60, or $5.7MM at age 65 (assumes an average return of 7% per year). That doesn't account for inflation, fees, etc. The average return of the stock market since the year 1900 until today is around 9.5%, so 7% is a realistic assumption.
There is a great website with tons of information you might want to check out:
http://www.bogleheads.org/forum/index.php
Members of this site follow Jack Bogle's (founder of Vanguard) theory of investing - low cost, broad index investing. Remember, investing should be boring...if you want excitement, by a motorcycle, jet ski, etc.
Something you should also consider is the purpose of this money. If you're looking for an income stream, typical long-term investment strategies won't work.