Some Master's programs do not offer much funding, though you may be given a partial scholarship and be eligible to apply for certain grants and loans. Since Master's programs are shorter and less expensive than Ph.D. programs, you can realistically plan to pay back loans. Also, your expense will often be offset by a higher starting salary in your field (over someone with just a B.A.). Other programs offer funding packages comparable to those described below for the Ph.D.
Most Ph.D. programs offer funding packages to all accepted applicants, usually some combination of fellowships, teaching assistantships, and loans. A "fellowship" means that the university pays your full tuition and gives you monthly stipends, with no teaching duties attached. A "teaching assistantship" is usually a similar package with teaching duties attached. Loans, of course, you have to pay back. In light of the current job market, it is wise to minimize the amount of your own money you spend getting a Ph.D., especially the amount of debt you incur. While it is realistic to expect to borrow some money at some point, it would be utterly unrealistic to finance an entire Ph.D. program with loans. On the other hand, if you are admitted to a top notch program without first year funding, and the odds of getting funding in subsequent years are very good, taking out a loan for your first year may worth it in the long run.
If part of your funding comes from a teaching assistantship, find out exactly what your teaching duties will be, and how much preparation for teaching the university will provide. Ideally, you will not be asked to teach during your first year of a doctoral program. In subsequent years, you will be asked to lead small discussion sections of large lecture courses taught by a professor. The program will provide you with training in teaching writing, and then give you opportunities to teach your own courses in both writing and literature (one course per semester). Unfortunately, many funding packages do not match this ideal. You may even be offered a package that requires you to teach two composition classes every semester, starting in your first year, without any training. While many students cope with such a situation, it can be nightmarish, even exploitative, and you would want to refuse it if you have choices.
In the case of an M.A. program in English, teaching opportunities may be rare, and granted only to particularly promising students. Depending on your career goals, you might want to look for programs that offer chances to do a teaching assistantship
If you do not get funding from the university, you may want to check into national grant and scholarship programs for graduate students (Mellon, Ford, Javits, National Science Foundation, Woodrow H. Wilson, others). Information about such programs can be found on the web; the UWSP Financial Aid or Grants Offices may also have tips.