what percent of my check each month can go to a house payment
Give yourself at least a $200 buffer (more if you tend to buy little things) and that's the absolute most you can afford for a mortgage. House payment shouldn't be more than 30% net income (what you take home). Any more than that you'll have a hard time living. Car and credit cards - zero. Don't carry a balance on credit cards because it is a rip off. Pay for cars because you can get upside down and cars depreciate in value.