The lighting you need depends on the size of your space. However there are only certain kinds of lights that work well for growing and regular light bulbs are not one of them. If you are serious about this, I would recommend getting away from fluorescents altogether. While they will grow bud, you just need a ton of them to be adequately lit.
If you are serious you are going to need to step up to HID lighting or a good quality LED. Right now, HPS lighting is still cheaper than LEDs, but LEDs have come a long long way in the last 5 years or so. A 400W HPS will adequately cover a space 9-10 sq ft. You would need about 800 watts of CFL lighting to equal the light from a 400W HPS. I would not go below a 400W light.
This is not an inexpensive hobby if you are growing indoors. Marijuana is a high energy plant and does have certain requirements that must be met. Adequate lighting is one of the most critical things in your grow--your yield will be directly tied to your yield. A single CFL, even a large one is only going to be good enough for when they are very small.
We have a Sticky in the Beginner Forum that has links to some basic grow books. I would recommend that you read a few to understand the needs of cannabis and the requirements for a grow space. Unfortunately if you do not have the money or a place to set up a small dedicated space, it is going to prove very hard to have a decent crop at the end of your 4 months of hard work.