I first ran into Escape Velocity (the original) when I was doing noon to midnight tech support in college. I needed games to keep me from going insane. Escape Velocity was the only thing I used the Mac in that little office for. More recently, the original authors of Escape Velocity made a PC compatible version called Escape Velocity: Nova. You may want to read this review if you're not familiar with the EV games. Or have a look at the wiki.
Real world entrepreneurs say that "the first million is the hardest"; after that it gets a bit easier. The same is true in Nova. I've haven't gotten a lot of sleep the last three nights, but I've learned a lot in the process. You start the game with a regular (non-heavy) shuttle with only 10 tons of cargo capacity. Which is basically nothing. And then you've got to find the good trade routes - always difficult. But let me give you some hints. One, you can hire -used- heavy shuttle escorts at Earth for only 499 credits each. And since your shuttle makes hyperspace jumps in one day, this is a lot better deal than it might first appear. In fact, I believe that these -used- heavy shuttles (which end up costing only 99 credits per day) are, bar none, the most efficient - in terms of profits per ton - rentable cargo ships. The rent on even an ultra-cheap Terrapin quickly makes them prohibitive. and forget renting an IDA Freighter.
Okay, so you've rented the maximum of 6 heavy shuttle escorts. Now, what do you do with them? First, make sure you have at least 10k credits. Part of this will be for cargo, part will to be pay your rented cargo shuttles. You're already at Earth, so load up fully on Medical Supplies. You should be able to buy about 90 tons worth. At 60 credits per ton, this will cost almost 6000 credits. Now, bring up the map and shift-click to plot a course from Earth, to Nesre Secundus, to HJG-1034, to Tuatha. Once you get to Tuatha, dock at New Ireland and sell your Medical Supplies. Notice that you bought them on Earth where the price was LOW, and here in N. Ireland the price is HIGH. Also notice that the price of Luxury Goods is LOW here on N. Ireland and it was HIGH on Earth. Are you beginning to get the idea? Buy as much Luxury Goods as you can. Just keep your credits above 2000 - or else your cargo shuttles will get PO'd when you can't pay them and will abandon you halfway back to Earth. When you get back to Earth, sell the Luxury Goods HIGH. The full round trip should have netted you ~40k+ credits. Rinse and repeat as often as desired.
(Note: All goods in EV:Nova have the same profit percentage. It's about 35% profit if you buy low and sell high, regardless of the commodity you choose. Thus, to maximize your take, you should buy and sell the most expensive possible commodity. That will net you the most credits per ton hauled. To make the same number of credits in, say, Food or Metal would require hauling a LOT more tonnage. Luxury Goods (Sol<->Tuatha), Opals (Formalhaut<->Lotus) and Duranium Ore (Sol<->Avalon) are all good "milk runs." I choose the Sol<->Tuatha run particularly because it's short, only 3 jumps each way, because you can carry high-value cargo in both directions, and both ends are heavily guarded by friendly ships to protect you from any marauders.)
What you do after you've made your first million is up to you. I, personally, decided I was going to do the Polaris storyline. So I needed a fast ship that was also very durable and could hold its own in a fight. There's only one ship that first this description - the Starbridge. Yup, the white whale-like ship that's on the loading screen. I happened to luck out and find a Modified Starbridge-C at the New Ireland shipyards and grabbed it. It cost about 850k all told, between the cost of the ship and all the @#$% licenses you have to buy from Earth for the weaponry it mounts. But it's a beautiful ship - easily the best ship under 1 mega-credit, and possibly the second best ship in the game, all around. I've tossed the light blasters and added a couple of Hail Chainguns to mine, and up-armored it a little bit. Been more than a match for everything I've had to fight so far - though I am generally fighting-averse. With some careful tactics, I was able to utterly smash a pirate Enterprise (three times my mass!) that attacked me. After I disabled him, I was able to raid 250k credits and 120 tons of Luxury Goods from the wreck! I'm hoping to find a better reactor so the shields recharge faster. It's the only thing I can complain about with this ship.
Oh, one more thing. If early in the game you meet a Vell-os at Earth and he asks you to help him? Don't do it. He's an agent of The Bureau and helping him will only lead to getting trapped in the most painful and protracted storyline in the game. Just say no. And then be ready for a quick getaway...