Let me introduce you to the rule of 72. Basically, this is a quick method of calculating the compounding interest rule. This rule says that if you divide 72 by a rate you will get the number of years it will take to double. So, if your annual rate is 7% (which is more or less the annual return of the stock market as a whole over a long stretch of years), it will take a little over 10 years to double your money. Some years are up, some years are down.
It's like the story of the tortoise and the hare - slow and steady wins the race.
Generally, with high rewards is a tradeoff of high risk. So, you do hear stories of people who have "done well in the market" - in fact, I'd probably be one of those people. I also have a chunk of money sitting in a savings account, because it's doing it's job there. Here in /personalfinance we tend to concentrate on getting your financial house in order before treading into the waters of taxable investing.
If you have "lots of money" sitting in a bank account, ask yourself if it's an emergency fund. If it is, then it's exactly where it's supposed to be, tucked away where it's safe and sound. Is it something that's being saved for a purpose in the next few years - a downpayment, for instance? Then it's where it's supposed to be.
Don't move money around and into things until YOU understand why you are doing it. Not because someone on the internet or the TV or on the commuter train tells you to do it, but because YOU understand - ah, this is a retirement account. It's this KIND of retirement account. It does this for me. It's invested here and in this fund.
Or - this is a CD, it does THIS for me. It's at this bank, which is insured by these folks.
Or this is a stock in company Y - my cousin Vinnie recommended I could double my money and offered to take me to a seminar...WAIT A SECOND...what is company Y? Why is the stock .03/share? What the heck does Vinnie know? Let me read this prospectus. Good lord they are selling shares of condos on the moon! Who is this man at this seminar and why is the SEC trying to arrest him?
Start over in the Wiki with "I have $X, what should I do with it" and then you might want to go to Vanguard.com and look at their insights page to read about what mutual funds are, etc.
Strangely enough, I'd recommend checking your local library for some simple personal finance books. Or even odder, watch a few Suze Orman PBS specials - find out why she's yelling at people for being stupid with money. That'll teach you a few things right there. Similarly, CNN's American Greed. That'll teach you to doubt all claims and check all backgrounds.