3 to 20% of the purchase price for a down payment. The actual amount depends on what kind of loan you get and how good your credit is. Your bank might offer a zero-down loan, but if you can afford to make a down payment, you should do so, because you'll get a lower interest rate and because your monthly payments will be lower.

1 to 8% of the purchase price for closing costs. You might not have to pay this up front. The bank might be willing to add it to your mortgage. (Add them to the mortgage if you need the cash, but pay the closing costs up front if you don't.) The actual amount of closing costs depends on how good a deal your lender is willing to give you, and the price of the house. The more expensive the home, the less the closing costs are as a percentage of the total price.

$250 to $800 in Miscellaneous Costs. These are things like the application fee for the loan, the fee for the bank to run your credit report, professional inspection of the home, and an appraisal (if you can't get the appraisal added to the closing costs).

Putting these three things together, on a $150,000 house you'll need
$4500 to $30,000 for the down payment (unless you get a 0% down loan)
$0 to $12,000 for the closing costs
$250 to $800 for miscellaneous costs

Total: $4750 to $42,800. Yes, that's quite a difference. You'll learn more about estimating the costs for your own situation as you go through this guide.