Most families spend roughly 60% of their income on the basics, which include housing, transportation, and food. Also factor in that you'll need money for unexpected costs, savings, retirement, credit card bills, insurance, entertainment, and everything else that comes up every month.
When searching for a new rental, keep in mind that it's important to select a home close to whatever you do outside the house. For instance, how close it is to your place of employment and the other things you enjoy.
How accessible is the area on foot? Does a public transit system exist? And if you have children, do you want to know if the neighborhood has decent schools or whether there are any colleges or universities nearby?