Money question for people that have gone to RDTC: How much to have in savings?

I've been talking to a Roehl recruiter for about a week and a half, have submitted my application, and am pre-hired pending a physical and acquiring tuition for school. I sent in a credit application to try and pay for school via that route, but my credit has taken a beating the past couple of years, and that's not going to be an option for me. I'm going to have to pay out of pocket for school, so my question to those who have gone to RDTC and then on from there is how much money should one have saved to live on from going to school up until paychecks start coming in from Roehl? I know everyone's bills are different each month, but I'm more or less talking about basic living expenses for the period of time that you're not making a paycheck---the money you need to feed yourself, acquire things you need, etc. Also, how long is the period of time from starting school until paychecks actually start flowing into the bank account? Any insight into this would be greatly appreciated.

 

Someone out there must have some insight on this, no?