you and me both buddy...I am trying to start a planted tank too and have been researching
About substrates I think most people would just recommend fluorite ADS or eco-complete. Although these get prohibitively expensive with larger tanks, it's only about $15 for a 15lb bag to fill a 10 gallon at most. They also tend to last forever, so you'll never have to buy another bag for your life. Don't cheap out on substrate....
I'm confused about lighting too but I do know that it's harder to apply the Watts per gallon rule to smaller tanks. With the hood you have now, I'm assuming it came with your tank. In that case, it's probably only good enough to grow fish in and not grow plants. There are kits at A H supplies that people like to recommend. You can also build your own enclosure for them if you're good with your hands (which I am not). Don't forget that you'll need a glass canopy in that case.
If you go beyond 3 Watts per gallon (which you probably will if you want to grow any plants besides java moss and ferns), I think you're supposed to have some sort of CO2 supplementation. There's a DIY article somewhere on the forum about creating your own CO2 generator really cheaply using yeast and coke bottles. You might also have to create a CO2 reactor to disperse it. I've heard though that you can just put it near the intake of your filter though but I'm not sure to what kind of filters that works for. A note about this is that recently it has been suggested that silicon tubing causes a lot of CO2 leaking, so you might want to use another form of tubing.