I don't know where to begin. Welding schools are o.k., but the only place to become a "certified master welder" is the school of hot slag and scarred arms. 700 hours of welding school is great, but it doesn't begin to get you good at welding. all you'll have is the time you spent in the test booth, so what happens when you go to work and you have to weld a joint that's 6 inches off the floor that's going to be MT'd? There's no substitute for real time under the hood.
40K isn't much if you break it down...About 850 a week BEFORE taxes. That's about 20 dollars an hour. I'm asuming that their job placement is shop welders. If you get into field construction, ie, Ironworkers, Pipefitters, Boilermakers, and Sheet Metal Workers, they make much better money than 40K...The money we make is only limited by the amount of hours that we want to work a year. Welding can be a profitable career if you're good.
Don't be cheap with equipment. Go out and buy yourself a good welding hood, a pair of leathers, a mill jacket, and some quality safety glasses. Most shools will supply most of the aforementioned items, but probably not a good hood...Make sure it's something comfortable that you could concievably wear 8, 10, or 12 hours a day without your neck getting too sore or your forehead hurting.
Oh yeah, don't get stuck learning just one process....they'll probably teach you how to run SMAW and GMAW...But don't stop there. Learn how to run GTAW, FCAW also... Get comfortable with each process you learn, because the more comfortable you are with it, you will make better welds. Learn how to run Stainless, Inconel, Monel, and other slightly more exotic electrodes, because the more you can weld with, the more money you'll make. I could go on and on all day, but I'll leave you with that.

I know the school you are wishing to attend. Are you thinking of going to the one in Jacksonville? or Tulsa. My friend was going to go to the one in Jacksonville because his aunt lived down the road from the school ( really cheap rent :) ) He soon found out that that is their new school and it was just a basic vocational school, it was nothing like the one in Tulsa, (unless it has changed in the past 2 months. We both spent 5 years in the Navy and that school was a recap of all we have already learned. The one in Tulsa was supposively really more advanced as well as offering the basics as well. If i were you i would get the lowdown again on the differences between the two locations, and if location permits, i would go to the one in Tulsa if you can.

David

also, a lot of welding schools might not teach you about other subjects involved with welding. you might become a great welder, but will you be able to fabricate your own pieces from the mill and weld them together to make the final product? you have to have some knowledge of geometry, some math, and some structural common sense. if you're going to be working for a contractor, or a big company, these things might be provided for you...if you're working on your own, YOU might have to do it all yourself. welding isn't just welding...it can turn into a big production if you want it to. like they've said before, a lot of it is experience.
oh, and to help you out, up here in alaska on the pipeline, welders make $25/hr and on the average put in 168 hrs in 2 weeks...that's 88 hrs of overtime...i'll leave you to the math. they work 2 weeks on, 2 weeks off.
good luck