There are some awesome real estate web sites like Zillow and Trulia that provide data on a national scale. They have lots of tools, and even claim to show you last sale price, tax information and more. Be skeptical of this information, however. The information on these sites is only as good as the local sources provide. Often, this extra information about properties are only estimates, and should be verified by the appropriate local professional.The way the national sites get their data is not consistent from area to area. Large metro areas generally have better quality data, as their property assessment and MLS data have been available online for many years. Smaller markets don't have the available data for accurate information, in most cases.Pay attention to your local web sites that show up in your web searching. The sites that are most 'on the ball' will generally show up when you enter an address for a property in a Google search, for example. Many real estate web sites only link to national sites to display their data - and those sites are generally invisible on the search engines. This is an important point when you are choosing a local real estate agent to market your property - you want to choose an agent who has a web site that shows up often in with a variety of internet searches. Many local agents do not have the expertise for their website to come up high in search engine results.With a good web real estate search, you can filter your searches by price, number of bedrooms, location and more. The more advanced sites will let you compare listings side-by-side, and have built in social media features so you can share your findings on Facebook and Twitter.There are lots of awesome real estate websites today that give consumers powerful features to help them find the property of their dreams. With powerful features and lots of helpful data, they can be of great help - but be careful about the accuracy of the data, remember some of the tax and sales information you read may only be estimates of the true data.