I am interested to know the most current survey information regarding the offering of benefits to temporary employees. What types of benefits are usually extended and if there are contribution requirements, is it higher than the regular employees.

EBRI (@ www.ebri.org). Chas. Spencer and the DOL sites may have data in tables which provide some of the information for which you are looking.

In addition, the large consulting firms (Segal, Towers, Hewitt, et al) provide this information to their clients and, sometimes for a fee, to others.