The bills aren't added up right and i need some extra cash for my shots for LPN school.
My question is: Do these things work and how? Do they go off credit? How do they determine how much you will get?
i'm in florida

Do not get the online payday loans. If you have to get a payday loan, at least go to one where you walk in a store and talk to the people who run it.

They do not run your credit, they go by how much you make in a pay period. The most they can lend is $425, and you will have to pay back $500. You will have to bring in your paycheck stubs, check book, a utility bill with your name and address on it, drivers license, possibly your SSN card and a pint of blood (ok, that last part was just being funny)

They will charge close to 400% interest on the loan, and a lot of people find themselves in a revolving cycle of just renewing the loan and paying the fee or interest. They are very difficult to get out from under.

Do not do this if you cannot get it paid off in the time frame of a month. Otherwise, you are going to get sucked into the cycle.

The ones on the internet tend to debit your checking account on the day the loan is due, and if it isn't in there, you get slammed with not only overdraft from your bank but fees from the payday loan.

Also, the ones you go to in person, you have to pay them back in cash..they do not cash your check. (unless you don't show up to pay them..LOL)

Also, be aware that in some states, Payday loans are illegal, and if you are in the military you can no longer get a payday loan.