The absolute first step to take is to talk with a mortgage person. There are a few reasons for this. First of all, you want to know where you stand financially in regards to qualifying for a mortgage. You will find out how much of a mortgage you qualify for, and how much you can really afford. Many times a bank will qualify you for more than you are comfortable paying each month. We do not want you to be what we call "house poor", meaning, yes, you now have a home, but you don't have enough money left over after paying the mortgage to enjoy life.
The second reason is that if your credit score is a little low, a good mortgage person will explain how you can improve your score... sometimes dramatically. It does take at least a couple of months for any changes you make to trickle down to your credit score. But it could mean paying a lower interest rate, and therefore have a lower mortgage payment, so the wait may well be worth it.
The last reason is that you cannot make an offer without a mortgage pre-approval. No seller will consider your offer if you can't prove you can pay for it. Also, you don't want to waste your time looking at $300,000 homes if you would only qualify for a $250,000 one.
No, the qualification is the same, but you may want to look into an FHA 203K rehab loan. This is a specialized mortgage that gives you extra money above what you are paying for the property that you can use for repairs and upgrades. Many foreclosed properties will need work.
With an FHA mortgage the minimum down payment is 3 1/2% of the purchase price. You will also need around 2% (roughly depending on the mortgage) for closing costs, but we can almost always get the seller to pay for most of that. The are other loans available through Mass Housing and the VA that have low or even no down payment requirements. Again, it depends on your particular financial situation. There are also matching down payment programs in many cities that I can help you with.
Everything here also applies to a short sale. The major difference is the length of time needed to close. With a regular home sale, including bank owned properties, the closing is typically 4-7 weeks after the offer is accepted. With a short sale you are looking at a minimum of 8 weeks, with 3 to 4 months more common, and 4 plus months not uncommonly seen. The saving you can make is usually worth the wait.