How many lumens should my light bulbs be?

Okay, I'm by no means a professional photographer and am very much new to photography. I have a Nikon D50 and I'd like to take some photos of clothing/people in an indoor space of about 10ft x 8 ft. I'm going to be using two fluorescent lights and some kind of diffuser. I don't want to use strobes because they're too expensive and my skill level begs continuous lighting.
One thing I'm having trouble finding on the internet is information about how strong the lights should be. Any suggestions?

Without a lot more information your question is difficult to answer… What color are the walls/ceiling? How high is the ceiling? What type of lights? What is the diffuser?

I don't measure my lights in lumens, I go by temperature color (3200°K/5500°K/etcetera for white balance) and watts (for brightness).

For example, in a 8'x10' area… I may run anywhere from 1000watts of light plus a speedlite to 3000w+ of constant (mains, hair, backfill) plus a couple of 600w/s strobes… It is better to have too much light that you can adjust (with scrims, 30°/45° grates, snoots, adjustable power, move it back, etcetera) than it is to not have enough ("you can adjust what you have, but you can't add what you don't").