If you are conservative and/or have kids, you can carry a mortgage amount of 2x your income.
If you are childless and/or very home-focused, you can carry a mortgage amount of 3x your income.
For most people, being in the middle at a mortgage amount of 2.5x is comfortable.
Note that I am talking "mortgage amount" not "house price."
To give you an example, if you make $100K a year, you can comfortably carry a $250K mortgage.
So if you want a $400K house, you'll have to put $150K down to make that work.
These guidelines work better than a "percentage of salary" rule, because you don't have to get into the whole before tax/after tax discussion -- and they account for the fact that people with kids may have tremendous school expenses.
author, "Diary of a Real Estate Rookie"
Insider Real Estate Tips with a Twist of Humor: http://tinyurl.com/2ag28z
My advice is to keep your mortgage payment as close to your rent as possible. It's ok for the mortgage payment to be a little bit more than your rent, because you still have to take into account the following:
monthly taxes (these can be written off!)
I'd be careful with mortgage brokers, I've been burnt several times in the past by ones right here in Pittsburgh. Let me know if you need a reference to 2 great lenders I know. What I do is use the both of them at the same time to get me the best rate, in other words, I let them both compete for my business.
The best way to get good mortgage is to:
1. educate yourself on the mortgage process
2. let two lenders compete