I trade futures after years of trading stocks and options.
I prefer to trade forex futures but also dabble in cocoa and oil. It's been a nice volatile year in cocoa with all the unrest in the Ivory Coast. My main bread and butter is the Euro.
The #1 most important thing I have learned is DON'T OVERTRADE!
I do quite well when I'm disciplined enough to limit myself to only a few high percentage trades. It's addicting as hell. I always want to have position on, and that gets me in trouble.
Yeah TOS sucks, but its free and there are some great traders in the chat rooms that you can learn from. The charting is good, but you can't trust the data in real-time. Every single time they update the software, they fuck it up and it ends up losing people money. Stay away when they do an update. Nothing worse that being in a trade and having TOS datafeed stop for 10 minutes. TOS is mainly geared toward option traders.
Chart and chat on TOS, trade on something reliable and cheap.
The best thing to do is pick one future/commodity that you like to trade and stick with it and master it. They all trade completely differently and have their own quirks. Stay far away from the low volume ones, and avoid most of the softs as they will rip your face off. I would also recommend staying away from crude and especially nat gas.
Also, don't expect that your results will mirror your previous results in paper trading, it's a completely different ballgame. Paper trading is good for learning the platform and testing new systems and indicators/studies, but there is no simulation for the emotional factor.