1. If you have a bank your working with, first I would get pre-approved. If not .
2. Find a realtor in your area and they will help you find the right bank or mortgage co. to contact.
3. The bank will let you know how much you can borrow.
4. Write down how many bedrooms, baths, area, yard, garage, type of home, price, school system you would want, discuss it with the person you will occupying the home.
5. Let the realtor know what you agree on and they will find you a home. Good luck.

It looks like Martha answered her own question, but I agree with the answer. I would add that you should have some idea of your wants and your needs. There are often quite different. Make up a sheet with two columns and label them WANTS / NEEDS Then get going and start your list. Do you want 4 bedrooms or would that just be nice to have? How about location. style of home, handicap accessibility, nearby attractions, distance from work? Do you want a condo unit or are you independent and want to mow your own grass? This will save you and your agent a good deal of time. Do not hesitate to look on-line for properties and to get some understanding of what is available and at what price.
PS when you start looking your wants vs needs will change!

The first thing to do is get preapproved, so you know how much you can spend. A preapproval has to be part of any purchase offer you submit. You can get a pre approval at any bank or credit union that you do business with or you can get one at any mortgage company. Then you need to contact a real estate agent and start looking for your next home.