It's awfully illiquid and not subject to some of the same scrutiny that other stocks would be. If there's a stock there which you know inside and out (not just because some e-mail told you that it was going up today or a talking head on CNBC mentioned it), and you feel comfortable taking a small piece of your risk capital (my suggestion is < 5% of your investable assets for this type of a fence swing), then go for it. Just be prepared to lose it all. I think you can get a higher risk-adjusted return elsewhere for your fence-swinging money (small business, real estate), so it's not where I put my money.
Really? There are thousands of real companies that are liquid and earn profits. Why make this hard on yourself? There are no honest books on OTC investing - oh wait here is a title - "How to make thousands in penny stocks starting a million dollars" Better yet - why not an honest conversation with yourself on what you are trying to accomplish. You invest to offset future liabilities. A low cost index fund along with a solid financial plan will keep you away from get rich quick schemes.
Mathew, it is not the type of thing I recommend, as I feel it is quite risky. And I try to manage risk. These markets often move based on people promoting the stock with wonderful stories. Often, they are just stories.
My opinion, is, in general, the really, really, smart people are right 60% of the time. So lets say you are one of them. Even then, that means you are wrong 40% of the time. If you are making high risk bets, that could wipe you out before the odds give you some big wins.
If you love that thrill, I urge you to do it with a very small percentage of your disposable assets. If and when that money is gone, I urge you to give it up