(http://www.acdlabs.com/iupac/nomenclature/) gives the rules of nomenclature for organic molecules. It is divided into sections based on the class of compound being named.
Online Periodic Tables
The Visual Elements Periodic Tableby the Royal Society of Chemistry. (http://www.rsc.org/periodic-table) This unique periodic table combines art with science. In addition to giving nomenclature and physical property information for each element, each chemical has a piece of visual art associated with it.
Periodic Table: Webelements(https://www.webelements.com/) This periodic table comes from the University of Sheffield in the United Kingdom.
Most Beautiful Periodic Table in the World(http://www.periodictable.com//) Theodore Gray's "Most Beautiful Periodic Table in the World" brings together the best of his collection of thousands of pictures of element samples. This site also includes lots of information about the elements, as well as many more pictures of each.