Thinking of going on for a PhD-How much does it cost?

I have a graduate degree and am thinking of pursuing a PhD to ensure a career of research and teaching in my field. I'm embarrassed to ask this, but how much will this cost me? I have a family and can't really devote too much money to this. Can you tell me about fellowships and aid? Does the tuition for a PhD usually come out of pocket?

Well, honestly, how much it costs varies on whether you will be "in-state" or "out-of state" and for what degree you are persuing.

I can only speak of science related Ph.Ds (which I hope is relavent, because you mentioned "research").
Usually, as a Ph.D candidate, you will have your tuition paid for through your advisor. To clarify, when you begin your Ph.D, you will choose a professor whose research interests you, and will be working in his/her lab for the duration of your candidacy. During that time, you advisor can pay your for your research (similiar to a paycheck), and pay for your tuition through the use of their grant money. But how much they pay, or what they will cover depends on the school, and on the individual advisors grant money.

Fellowships are usually common, and can pay for a lot of the tuition, however they usually have GPA requirements to maintain eligibility. There are also Teaching Assistantships, which require you to T.A. some undergraduate classes, and you are paid some money.

Now.... I assume you already have a Master's because you state you "have a graduate degree"... so you must understand that MOST of you Ph.D will be your performing research in your lab, and writing your dissertation. From what I know, you're almost required to be in lab 7 - 8 hours per day... if you aren't in the lab for that much, the degree may take many additions years (which means additional tuition money!).
Remember that when you go for a Ph.D, that IS your job. You won't be able to work a full-time job on TOP of your degree. That is why the school usually helps to pay for the tuition and give you stipends/research money.

If you have more questions on PhD. programs, I can do my best to help you out, you just message me.

Good luck.

a lot.... why you are in college have a job and save ok.