Once you've found a house you like, you must make a written offer to buy it. Exactly what form that offer should take depends on what state you live in.
In some states, the standard offer is a bare-bones statement that "I'll take the house for $X," after which the seller writes up a draft contract. In other states, your offer must be so complete that the seller could sign it and you'd have a contract right there.
Deciding What Price to Offer
The advertised price of a house is just a starting point. It's up to you (and the market) to decide how much the house is really worth -- whether more, less, or exactly the offer price -- based on such factors as:
- how much comparable houses have recently sold for
- the house's aesthetic or other appeal to the average buyer
- whether the local real estate market is hot (demand for houses is high, and prices are going up, with you perhaps competing against other bidders) or cold (prices are dropping, and houses staying on the market for a longer time)
- whether, in fact, any other prospective buyers have shown serious interest or put in offers
- the seller's needs, such as to move quickly, or to unload a house that's been on the market for several weeks
- the house's physical condition (which you may not find out much about until you do an inspection, which a few buyers actually arrange to do before making an offer, though most wait until they're in contract)
- whether the house is uniquely valuable to you, for example if you need an in-law unit or art studio, and
- what you can afford, after a careful examination of your budget.
After considering all these factors, you may decide to bid thousands of dollars less -- or more -- than the seller is asking for. You'll need to be strategic here. Obviously, you don't want to overpay. But offering too low a price on the mistaken theory that the seller will come back and negotiate for more could result in you losing the house to another buyer or insulting the seller to the point where he or she refuses to negotiate.
Adding Contingencies to Your Offer
Real estate offers almost always contain contingencies -- events that must happen within a certain amount of time (such as 30 days) in order for the deal to become final. For example, you may want to make your offer contingent on your qualifying for financing, the house's passing certain physical inspections (see Nolo's article Getting a Home Inspection), or your ability to sell your existing house first.
The seller may also add contingencies to the offer, such as a condition that he or she have found another house to buy before closing the sale to you.
For more information on your options when it comes to contingencies, see Nolo's article Contingencies to Include in Your House Purchase Contract.
For a detailed analysis of how to decide the right price for a house, craft an offer tailor-made to your and the seller's needs and interests, and negotiate the final contract, see Nolo's Essential Guide to Buying Your First Home, by Ilona Bray, Alayna Schroeder, and Marcia Stewart.