Low Tech Tank Lighting
If you keep plants that require low to moderate light, then GE aquarium plant bulbs from the local hardware store are fine and cost no more than $10 to $12 each. Just look for bulbs in the 6500K range. These come closest to natural daylight at 5500K.
Larger tanks will take a 48 inch florescent bulb, a T8 or T12. Ideally, you want a hood or strip with places for 2 bulbs.
When you have the lighting in place, you want to use a timer so the light comes on and goes off at the same time every day. I have my lights on for 12 hours on and off for 12. The reason is, most aquarium plants come from areas that get long hours of daylight.
Aquarium plants also need a lot of pure water. I remove and replace half the water in my tanks weekly. This maintains high levels of phosphates, sulfates and nitrates the plants need.
I also dose a little liquid fertilizer a couple of times a week. I use Tetra's "Flora Pride". I just dose a half a cap or so in a pitcher of replacement water when I need to replace water that's lost to evaporation.
These are the basics. Pretty simple.
"Fear not my child, just change the tank water."