Never invest money in anything that you do not thoroughly know, be it stocks, a “once-in-a-lifetime opportunity” or a new TV.
In order for an investment to be an investment and not plain speculation, you need rock-hard, objective facts. Without facts, you either just gambling (which is a VERY risky way of “investing” your hard-earned money) or your putting a value on something just on the basis of what someone else has said. If that somebody has his own interests in the issue, it makes your decision also very risky.
Just think about buying (investing your money in) a new car: The seller will try to raise the value of the car either by lying or just showing the “good sides” avoiding any problems the car might have. Your job as an investor is to get the truth as truthful as possible. 
How do you manage that? Investor’s #1 rule:
Know what you invest in
Get as many facts as possible from as many independent/objective sources as possible.
Never rely on just what somebody said. Verify the information. Objective information is your power and your insurance. Speculators base their decisions on subjective information. For example, they invest in stock just because it has gone up, not because it’s underlying value rose. Or as Graham put it once:
Investors judge “the market price by established standards of value,” while speculators “base [their] standards of value upon the market price.”
Below is a simple graph that shows how manipulable and, therefore, risky speculating is:
