I've been playing Freelancer off and on for a long time now, mostly with a group of buddies in the vanilla game. Found out about Discovery and decided it would be a good time to get back into the game. I'm in college so I might not be online a whole lot but I look forward to trying this mod out and getting some great RP in!
Helium Mining is especially lucrative if you do it with a buddy. Talk to your fellow miners there. One miner and one Hauler are able to cash up quicker together then 2 miners alone. Check out the Omega 7 System once you got enough cash for a ship upgrade. You can mine more valuable stuff there (go there and see for yourself) and the yield is even better.
Welcome, listen to Vanalvo's tip, mining helium in Pennsylvania is a good way to get bigger trading ship. Of course if you are interested in good faction to start, you should consider some trading/mining faction. In DHC members are helpful, and every new member gets free starting ships.