When you put your contract in, you pay an earnest money deposit, which is typically $500-$1500 or higher, depending on price of home. This goes towards your down payment and closing costs, so thats good news.
Next, you should always have a home inspection, which runs about $200. It's definitely worth the cost, but should be paid usually at the time of inspection.
Typically, if the home inspection comes back, you must order the appraisal, which is also paid immediately and usually runs around $400 in our local area.
After that, there are no upfront costs until closing.. at closing, the seller typically pays for a survey and termite, as well as septic tank inspection if necessary. The seller also pays for part of the title insurance and the state taxes on the deed.
As a buyer, you usually pay for part of title insurance, a years worth of insurance, a few months of property taxes, lender fees, taxes on the mortgage to the city and county, and recording of the mortgage. You can negotiate to get the closng costs paid by the seller, or atleast a large majority of them. We typically say to expect about 3-5% of the purchase price in closing costs at closing, but that all depends on the ctonract. Your realtor and mortgage professional should be able to give you more exact numbers! Let me know if you didnt end up buying anything and are still looking to take advantage of the home buyers tax credit before April 2010!
In most markets, it is pretty common for the Seller to pay all or a portion of Closing Costs. When you get a Good Faith Estimate from a Lender you should have a fairly solid estimate of your Closing Costs so you should try and negotiate that the Seller pay those costs.
You should be prepared to pay for the Appraisal and Inspection (If you have one performed) out of your pocket and prior to Closing. You will also have to put some sort of Earnest Money down when you sign the Contract; however, this will be credited to you at the Closing.