Visual Periodic Table of Elements: Great visual images of elements, where they come from and their uses, w/some properties.

Periodic Table: Quick reference for number of protons, neutrons and electron.

Chemistry Explained: Perfect for finding properties of each element.

Elemental Matter: Fabulous site for finding properties of elements easily.

Chemistry Explained: Totally rad easy to use site for properties etc...also has common compounds and materials.

PubChem: 3-D rotating molecules and easily searchable database of compounds, element etc...

Dynamic Periodic Table: The best periodic table on the internet, you can change it print it etc...

Royal Society of Chemists: Nice, basic, easy to find details about each of the elements.

Periodic Table of Videos: Super fun interesting videos and real chemistry for each element.

The Elements: Created by the Theodore Gray who made the incredible coffee table book.

Webelements: Another simple but easy to navigate site about the periodic table.

It's Elemental: Has quizzes, flashcards and other study tools to help you learn the periodic table symbols.