Author
It can sometimes be difficult to find out who the author of a website is. Remember that an author can be a corporation or group, not only a specific person. Author information can sometimes be found under an "About" section on a website.
If there is no known author, start the citation with the title of the website instead.
Date
The best date to use for a website is the date that the content was last updated. Otherwise look for a copyright or original publication date. Unfortunately this information may not be provided or may be hard to find. Often date information is put on the bottom of the pages of a website.
If you do not know the complete date, put as much information as you can find. For example you may have a year but no month or day.