I always start with a generator on its own connected to a macerator and furnace. You'd be surprised how little power you need, probably a stack of coal is enough to get you through the early game, and it is very common in caves so it is fairly easy to get a large amount. My advice would then be to set up a nuclear reactor as fast as you can. As dangerous as it sounds, nuclear reactors are the best source of energy in industrialcraft and require the least amount of materials to maintain. Obviously the main detractor is the cost of making one, but with your materials at the moment I can't see it being too difficult. The clear danger here is a nuclear meltdown, which is absolutely devastating and will destroy everything around the reactor. However, using redpower or Project Red, you can use circuitry to make a meltdown an impossibility. You'll need a thermal monitor on the side of the reactor set to emit a redstone pulse when the reactor's core temperature reaches 500 degrees. Industrialcraft reactors are somewhat unrealistic in that their "operating" temperature (i.e. when all uranium cells are touching 1 coolant cell) is less than 100 degrees. From the thermal monitor connect redstone to a toggle latch, and that output back to the reactor. It should look something like this:
That will ensure the reactor never overheats, as it will shut itself off as soon as the temperature inside gets too high. From there you can increase automatic maintenance, and potentially end up with a system like I've built in many worlds which will automatically produce a coolant cell whenever the reactor needs a new one. In terms of the materials used to run the reactor, all you need for a starting reactor is a uranium cell and a coolant cell, arranged something like this:
You will need to fairly regularly replace coolant cells when they run out, but that is all the maintenance you will need to do. If you need more power, all you need to do is add more uranium and coolant cells. In short, an amazing source of power with a low running cost.
NOTE: These screenshots are taken from tekkit rather than FTB, but the industrialcraft principles remain the same.
EDIT: By request, recipes and automation details.
EMPTY CELL:
REFINED URANIUM:
URANIUM AND COOLANT CELLS:
ADVANCED ALLOY:
INTEGRATED REACTOR PLATING:
REACTOR CHAMBER:
NUCLEAR REACTOR:
ADVANCED CIRCUIT:
And finally, some screenshots of a system automating the production of coolant cells:
This system will first detect when the reactor overheats. It then immediately shuts off the reactor, and a new coolant cell is put into the reactor from the chest in the corner. In the meantime, on the top of the building, redstone machines are fetching the parts for a new coolant cell; i.e. a cell and a water bucket. It then makes the cell using automatic crafting tables and feeds the water cell into the extractor (which can't be seen in the screenshots). This extractor then pumps the cell into the chest in the corner. During this time, a timer has been timing 10 seconds, after which time the coolant cell has been completed and the reactor restarts. The most complex part is manufacturing new coolant cells. It would be a simple process, were it not for the fact that each recipe produces 16 cells. On the top of the building, a counter is incremented every time a cell is made. After 16 cells have been produced, 4 tin ingots are pumped up from the ingots chest downstairs, ready to be crafted. The counter is then reset.
