How much of your salary should typically go towards rent/mortgages?

I am soon graduating college and looking at potential places that I may find a job and move to. I am also taking into consideration the affordability of housing in certain areas. I'm trying to base this on average starting salary in my field, and how much I would be able to spend (likely renting for a few years at least).

I hold a job currently, and I pay for everything myself besides rent. I am fair at saving money, and am also trying to save up prior to moving so I can cover any down payments or other expenses, as well as have enough extra for a few months rent.

I am also willing to live a little bit under what I can afford to save money.

Thanks for the help!

Edit-

Wow, I got more responses than I though I would. Thanks to those who replied!

More info: My tuition was paid for by scholarships. I have no student loans, car payments, or credit card debts- I'm pretty fortunate. I'm hoping to land a job with an entry level salary of about 40,000 (teaching), which currently appears doable based on the areas I am looking at and current availability of jobs (which I know may likely change- I have a year left before graduation). I'm currently 22, and I will probably also be living with a friend for a while.