In addition to the mortgage, what other costs should I prepare for? There's obviously taxes, but what else what do I need to prepare for?
The general required costs that come with owning a home are (in addition to taxes):
1. Homeowners Insurance - the only way you can get away with NOT having this is if you've paid cash for the home and there is not mortgage, but any bank will require homeowners (aka "hazard') insurance if they hold the mortgage.
2. Utilities - If you've been renting where utilities are included, this may be a challenge for you. Gas, electric, phone, water/sewage, and trash pickup are the general ones. There's also cable/satellite TV or hi-speed internet access, and monthly security monitoring if needed. Many people are doing away with home phones and just using their cell phones.
3. Will you maintain your yard or pay someone to do that? Figure that in. If you maintain it yourself, don't forget that you'll need a lawn mower and tools, supplies, gas, and may have a higher water bill to water your yard. When looking for your new home, pay attention to how much yard maintenance there is. This can be costly.
4. Miscellaneous -- Do you need to make repairs or make changes to your home once you move in? You may need cash for improvements such as paint, new carpet, appliances (washer and dryers often do not come with the home). Also have cash reserves for repairs that may pop up later.
5. I suggest getting a home warranty on your new home when you purchase it. They range about $400 per year but they cover appliances and most major systems of the home - HVAC, plumbing, etc. Often, you can ask the seller of the home to pay for this upon settlement. Ask your Realtor for details if you need a reference for a local Home Warranty company.