Need help with citations? Beginning this semester Penrose Library is offering the Chicago Manual of Style Online. The online version offers the a searchable full-text version of the 16th edition, published in 2010, as well as the 15th edition from 2003. Other notable features include the Chicago-Style Quick Citation Guide and, for true grammar and usage enthusiasts, the popular Chicago-Style Q&A.
As a bonus for history buffs, check out the original 1906 publication: Manual of Style: Being a compilation of the typographical rules in force at the University of Chicago Press, to which are appended specimens of type in use.