Renting my first apartment?

I'm 20 years old and living at home for the summer. My family lives in the same town where I go to school. Things are really tense between my family and I right now, and I need to get out of my house. I'm looking at apartments right now. I'm obviously a poor college student, and my parents aren't going to want to help pay for rent. I make $750 or $800 a month, and the cheapest rent I can find is $450 all bills paid. I have some money saved up, and I know that I can do this if I live cheaply, but I've heard that landlords do checks to make sure that you make at least 3 times whatever the rent is. Is this true? My parents will most likely be co-signers on my lease. Will that help? I'm just overwhelmed right now, and not sure what to do.