Welcome to "terrariuming"! A 10-gal tank should be fine; I have 2 of them. "The lid to the aquarium has a fluorescent light fixture ... it has several "holes" punched out..." Is it a regular aquarium hood? If so, I think any light you find for it should work. I have a plant/aquarium light in one terr., and had a cool white bulb in the other. The cool white was brighter, and I think the plants under it grew better than the ones under the plant light. The cool or warm bulbs are cheaper to buy, also.

You might be able to put the terr. in a north window and use natural light, as long as the plants don't have a high light requirement. I have not heard of doing this or done this before, so I really don't know much about it.

If you get demanding plants, you might need more air circulation; otherwise, it should be fine without it. Neither of my 10-gals have a fan of any kind.

The best substrate? Now that would be a loaded question. the more exotic you get (water features, animals of any kind, orchids, etc.), the more specific kind of soil you'll need. With just plants, you shouldn't have to be nearly as specific. I have regular potting soil in both of mine, but it is not ideal. If you want a very easy substrate that is fairly cheap, coir (coconut husk fiber) will probably work just fine. Many people have their special soil mix that they always use, and maybe someone else will pipe up with theirs. I probably have less experience than most of the other people on here; from my experience I would recommend coco husk fiber. One brick of it will probably be enough for a 10-gal, though I don't know for sure.

For plants, there are many, many options. I personally like English ivy a lot. It has worked well in both of my terr.s, and it isn't one of those ones that will die if you take your eyes off of it. It does grow fairly quickly, so you will likely have to trim it some. Trimming is not very difficult, though. Some other good ones are Polka-dot plants (Fittonia), ferns, mosses, bromeliads, and Pothos (devil's ivy, will also probably need trimming). There are a lot of others, but they're not coming to mind right now. Most of the plants you are likely to want can probably be gotten at a local nursery. For moss, and maybe ferns, you can collect samples from your yard, or anywhere where you have permission to. I believe that the reviews you've heard for Black Jungle are correct. I have not had any first-hand experience with them, and I don't plan to (at least on plants). I have heard various people here give their much-less-than-favorable accounts of plants from Black Jungle. I think Black Jungle would be a fine place to buy supplies from, but not plants that you want to receive alive.

I hope this helps!
-Jmcat