All the resources I will mention below can be found on our How to Cite APA guide.
First, I recommend using the library's free citation management software Noodle Tools, if you aren't using it already.
Next, this quick reference (1 page) on APA shows the basic format for citing websites:
Last, F. M. (Year, Month Day). Article title. Website Title. Retrieved Month Day, Year, from URL
Some websites don't clearly show an author name, date, or even title. If you can't find the author name, the page title takes its place as the first part of the citation, for example:
Six sites meet for comprehensive anti-gang initiative conference. (2006, November/
December). OJJDP News @ a Glance. Retrieved from http://www.ncjrs.gov
/html/ojjdp/news_at_glance/216684/topstory.html
If the date is missing, use (n.d.), for example:
O’Keefe, E. (n.d.). Egoism & the crisis in Western values. Retrieved from http://
www.onlineoriginals.com/showitem.asp?itemID=135
Some kinds of web sources, such as tweets, blog comments, Facebook posts, and others, should be indicated in brackets, like this [Facebook page]. If the content has no title, those brackets take its place. Here's an example:
American Red Cross. (2009, November 2). Red Cross workers in American Samoa:
2 stories [Facebook note]. Retrieved from http://www.facebook.com
/note.php?note_id=178265261423
My last advice is to make your citations as complete as possible; look through the page thoroughly before deciding to leave out the author name, date, or title.