I've always heard a rule of thumb to be 1 and 1/2 times the amount of the salary. In your case...$75,000.
However, salary is one simple factor in the home loan process. Of course, credit status is a very big player in the home lending game. Something called the "debt to income ratio" is going to come into play when a company extends a mortgage. This means how much monthly obligations (this is car payments, credit card minimum payments, etc.) added together and divided by your monthly income. Many companies will not lend if it is lower than a certain percentage (although they cannot refuse to help you apply.) But, of any kind of loan, there are more companies than any other to help people of all kinds of incomes and credit statuses to get a mortgage. Why? Because a mortgage is generally secured with collateral (the house) which will not lose the bank money in case of foreclosure and they have to take the house from the owner and sell it to recover their money.
The best thing I can advise is this: go to your bank or chosen mortgage lender and ask to be "pre-qualified." This means, they are going to take a look at your credit and income and tell you how much they will finance you for before you even start the home hunting process. This lets you know exactly how much payment to expect every month, which houses you will and will not be able to afford, and keeps people from getting their heart set on one home and not being able to afford it. Good luck!