This is an excellent explanation of diagnostic criteria for personality disorders. It explains the disorders in non-technical terms but a great deal of detail (this is a LONG article, but worth the read). There is a brief discussion of treatment options for the various disorders as well. Personality disorders are hard to recognize as "disorders" unless you have some knowledge of psychology, but it often makes it easier to deal with a person who has personality disorder-related interaction issues if you can understand what behaviors are due to an actual disorder rather than thinking that the person is intentionally treating you badly. I think this article does a good job of providing that information.