The first and most important thing you do is talk to a mortgage lender. If you go on a buyers calculator it will give you basic information but the calculator doesnt know how long you have had your job. Are you getting alimony? Are you carrying alot of debt? Did someone steal you information and open any accounts? It happened to me. You need to know exactly what you can afford and their be no other surprises. Dont work with a lender that asks basic questions and doesnt get into the meat of your finances at the beginning. Many lenders wait till the end and I have seen many bad surprises come about that should have been handled at the beginning. You should also apply with a couple lenders to see who has the best deals. All lenders are not created equally as i see certain ones that try to add points onto the loan at the end when its too late to change.
Once you obtain a preapproval then have your realtor find a house for you. You dont want to put the cart before the horse so to speak. When I first got into the business I was so excited to get a buyer that I would just show properties not knowing if the buyer would qualify. I never ever do that now.
If you ever want some recommendations on some great lenders I would be happy to oblige.