You are in for a wild ride with the pennies. They are typically listed OTC (over-the-counter) and not traded on exchanges (such as NYSE, for example). SEC pattern day trading rules will still apply through your broker so you will need to have a minimum of $20K in your brokerage account (online brokers are fine) if you are planning on day trading or short-term swing trading and making more than 4 round trip trades within 5 business days.
The problem with pennies is that they are very thinly traded. In markets there must be a buyer for every seller and vice versa. You may not find a buyer for your shares at the price you wish to sell which means you could be stuck with a zillion shares that no one wants to buy. Market makers facilitate the process with exchange traded equities but the bid/ask spread on pennies could be more than the unrealized gain your account is showing. It is definitely an ever-present danger when trading illiquid securities.
If you are a trading novice you may wish to try your hand swing trading exchange-traded equities for a while through any of the discount online brokers (TD Ameritrade, for example) just to get your feet wet while you learn what you are doing. They are at least stable relative to pennies. I would say $50K is the minimum to actually day trade exchange-traded funds. Even that is very much on the low side.
If you have very limited capital you can trade the spot forex market to again, get a feel for how markets work (though trading currency pairs is a very different animal from stocks). Minimum deposits are usually 50 bucks with fx brokers. You will need $500 to actually make real trades and keep your stops realistic and still have enough to meet margin requirements.
Pennies are probably the riskiest of all securities to trade (followed by fx). They are simply unpredictable IMHO.
To add to what you said, the market makers themselves are often on the make so the market, in addition to being illiquid, is rigged with the express purpose of fleecing hapless retail investors to enrich the insiders.
STAY FAR, FAR AWAY.