There's a LOT of advice you can use here so far.
I've looked at HUD homes...I've found some really nasty ones.
I found one GREAT one...I missed getting my offer in before an investor by a few hours...I could've gotten a $100,000 home for $57,000! What did I learn? Get a good mortgage broker! Some are lazy, some aren't. Don't go directly to a lender, a broker works for you and will HELP you get your rates down. If you have money for a downpayment, I wouldn't put more than 10% down (unless you have a huge store of money). Putting a few thousand down doesn't change your payments that much. That's why I'd recommend looking into an adjustable rate mortgage.
Depending on your financial situation, you may want to do a 15 year adjustable rate mortgage. You get a low rate to start with, and you can start paying your debt down much faster (hence, why I wouldn't put more than 10% down). Contrary to what some may say, get your mortgage taken care of first: Get your credit check, find out what you qualify for: this will narrow down your home search and make it more manageable. When you do this, sellers will take your offer seriously because they KNOW you've got a lender's money to give them. Without that, how would you prove you can truly get their house?
If you want to look at HUD homes, get ready. You will be greatly dissappointed for the most part, but there are great deals out there. Develop a thick skin before looking.
Check out your local courthouse and find out how much people paid for the homes you're interested in...that is public info! Don't get scammed. Things listed with realtors (except foreclosures) are typically priced about 15% higher than they should be. Don't be scared to offer far less than asking price. My realtor liked to laugh when I'd give her an offer to submit.
Look at realtor.com They've got a TON of homes from all over the U.S. listed. You can find homes in the areas you want. When looking, be sure to read the small blurbs...you can lots of times tell what kind of sellers own the house: if you see words like "meticulously maintained", or other similar things...you've found a seller that wants top dollar.
Always, always, always, have the home inpected before you buy it. Pay attention to the roof, look for water damage in the house...look for termite damage. Don't fall in love with a house before it's inspected. If you want a fixer up, make sure you're ready to work with it.