You can use the "Advanced Search" option to narrow down the results you receive. Once you have a list of results in front of you, you can use the "Sort by" drop down, located at the bottom of the results, to change which houses appear first. Options include by price, by photo, by location, and many more. When you find a specific home you like you should save it, so you can easily get back to it later.
We update our site on a weekly basis and the information we get is dependent upon the listing providers we pay to collect property information. Therefore, we cannot provide a specific date as to when a home will be removed from the site, but I can tell you that nothing in our database should be older than 3 months, provided our listing providers (and their sources) are actively maintaining their own data.