My advice is all rather general, and I am not at all familiar with these new tax incentives:
Start by figuring out what you can afford. You can find plenty of on-line calculators that'll help you with this. Figure up what your monthly payments will be, and know this information before you start looking.
This is important: Do not spend as much as "everyone" says you can afford. Many of the people who offer this advice are trying to sell you something. If you buy at the top of your price range, you are tying yourself into spending every extra dollar on your house -- and you're tying yourself into doing it for the next 30 years. So you have a baby and you want to stay home a year; if you've maxed out your mortgage, it's probably not a choice. You have surprise triplets and you literally can't afford to work because of the daycare cost; too bad, the bank doesn't care. One of you loses a job, one of you becomes sick, you want to start a business . . . the list could go on. There's also the danger in many parts of the country that your house could go down in value, leaving you owing more than the house is worth. In short, do not buy "as much as you can afford". You can't afford it!
Decide what you're willing to pay. If you believe what I said in the above paragraph, it's less than what you "can afford". Real estate and mortgage professionals are trying to earn bigger paychecks for themselves; if they can sell you "more house", they get paid more. They aren't necessarily looking out for your best interests. That's YOUR job!
Make a list of your must-haves (3 bedrooms, 2 baths) and your wants (home office, fenced-in back yard) and start looking at houses. Be realistic. Sure, you see 20-somethings on HGTV moving into 5-bedroom mini-mansions with inground pools, but that's not the real world, at least not for most of us. When you see "what you can afford" and you start to be tempted by granite countertops, saunas, and built-in outdoor kitchens, refer to that list. If those luxury items are within your "what I"m willing to pay" range, wonderful -- enjoy them! If they're pushing you to the top of your budget, keep looking.
Do you have a decent downpayment? You'll need to put something down. Nothing-down offers cost waaay too much in the long run.
Do not put ALL your money into the downpayment. You're going to have some expenses with moving: Perhaps the carpet will be very worn, perhaps you'll need to buy a refrigerator. SOMETHING will cost you money as soon as you move into the house. For us, it was something like 6-7 things in the first month, and we were seriously wondering if we'd made a mistake. Aside from emergency money, ALWAYS have AT LEAST one mortgage payment in a never-touch savings account.
Investigate all your financing options. For example, if I were buying a house today, I would definitely look at my state employee's credit union. They usually have much better rates than the banks. On the other hand, when we bought our first house, we bought through a first-time homebuyers program offered by the government. It was a good rate.
Do not allow yourself to become too attached to "your house" until you've made the deal. Throw out a low-ball offer to see if your seller will take it, or if he'll come back with something lower. In today's market, you might get lucky. On the other hand, your agent knows your area. If he or she advises you that you'd better jump at something, listen.
Before you make any offer, know what you're willing to pay. If you and the seller can't come to terms, be ready to walk away. You're looking for your first house, not your dream house. You can't afford to sink all your finances into this house.
If you have a feeling the seller won't come down on price, ask for other things instead: Ask him to pay the closing costs -- not quite all the closing costs can legally be paid by the seller, but the lion's share can. As him to leave the dining room set or the washer/dryer. It's okay to ask him to fix the shakey deck, or it's okay to ask for a $2000 allowance for new carpet. This can be a big savings to you. It's okay to ask for ANYTHING to be left: light fixtures, curtains, anything. The seller can always refuse, but you won't know if you don't ask.
This is big: You want a simple-interest loan with no pre-payment penalty. Once you have that loan (and that house!), pay something extra every single month. Just a couple dollars, earmarked to go straight to the principle. As a rule of thumb, every dollar "extra" you pay saves you $3 in interest later, and -- obviously -- it brings closer the day when the house is completely and totally YOURS.
At the closing, do not allow yourself to be rushed. Be sure you understand to what you're committing yourself.
Get a home inspection.
Have a lawyer do a title search to be sure there are no liens against the house.
You may be tempted by a fixer-upper. Think carefully before embarking on this adventure. It takes the right person, with the right spouse, and the right set of skills to do this and make it profitable. Do you really have the knack? Do you have the motivation to come home and do this after your real job? Is this house going to really be something when you're done? For some people, this is a great choice, but tread carefully.
Once you're in the house, don't feel that you have to have it perfect right away. Take your time, paint a room here, buy a piece of furniture there . . . do it bit by bit, and don't go into debt for it.
And good luck!