Thank Vahab Moradi for recommending this page, it is a great deal of help for me. Yet I still need a source (standards and cutoff criteria) for interpreting and reporting the results of sobel test and other scores.

You should take a look at the link below. Dr. Hayes has a number of SPSS macros to do mediation and moderation analyses as well as excellent papers detailing their usage.

http://www.afhayes.com/spss-sas-and-mplus-macros-and-code.html

You can find a video of Andy field on youtube where he used macro of preacher and hays for mediation and moderation