Penny stocks are stocks that trade under $5 per share, per the SEC's definition. However, most people think of these stocks as under $1.00. Regardless, they pose serious investment risks as they are very volatile and illiquid investments. Watch out. The biggest concerns, of course, is that there is limited information on these companies, as you already know. Other concerns include a large bid/ask spread (little liquidity), very little public knowledge, and they are micro-cap companies. They are very small and the probability that they go under is immense. These companies typically have no revenue, little assets, and no real analyst is following them. People who typically invest in penny stocks are obviously speculating on unsupported whims.
Additionally, OTC penny stocks do not have minimum listing standards via the SEC. In short, they are so small that they do not have to file public reports.
Given these facts (little knowledge about the company, illiquid securities, little-to-no revenue, no stock analyst following, no track record, minimum reporting requirements), it is unwise to invest your capital in these stocks.
Bottom line: avoid at all costs.
Penny stocks are stocks which sell for under $1.00 per share. Note that the absolute price of a stock share has nothing to do with the worth of that share. Penny stocks are usually traded on the Over The Counter (OTC) Pink sheets. The name is from the fact that pricing was historically printed on pink paper for these stocks. Penny stocks are very illiquid which means that they do not trade very often, price information is hard to get, and there is a big difference between bid (price you buy a share at) and ask (price you sell a share at). The upshot of all this is that the penny stock marketplace is easily manipulated and an area with a lot of fraudulent activity. Many of those who are "trading" in penny stocks are really gambling without understanding the rules. And remember, if people are manipulating the market, then there are other people who are being manipulated and are losing money.
All that being said, there are legitimate investments in penny stocks. But I would only recommend them to someone who understood the market and really knew the company involved. And even then, there is no point buying and selling these shares quickly because the pricing is so poor. You really are speculating and the risk of loss is extreme in penny stocks.
My first question is: why do you want information on penny stocks? Are you trying to hit a homerun or further diversify your portfolio?
If you are trying to hit a homerun, I can't in good conscious tell you where to get information because all the odds are stacked against you. It's the investing equivalent to putting all of your money on 00 on the roulette wheel in Vegas.
If you want to further diversify your portfolio, I would suggest acquiring access to penny stocks through a microcap etf or mutual fund. The majority of your average investors doesn't understand that microcap funds purchase penny stocks. If you go this route, a professional manages your money and makes all of the decisions regarding the penny stocks while you sit back and reap the benefits.
Don't fall in love with the homerun strategy. It's extremely rare that it ever works, and your neighbor/in-law/coworker who told you they tripled their money in 4 months by day trading penny stocks is a liar.
I wouldn't recommend any average investor invest in penny stocks but if you are going to you should know to be very careful because there is a lot of risk and fraud in that area. To show a recent example of fraud in the penny stock realm check out the below article from yesterday in the New York Times. http://www.nytimes.com/2014/09/12/nyregion/290-million-lost-in-penny-stock-fraud-prosecutors-say.html?_r=0