Palaeos: The Trace of Life on Earth - Dedicated to providing detailed information on the history of life on Earth. Addresses palaeontology, evolution, geochronology, systematics, and ecology.
Steve Rose's Evolution Timeline - Offers a proportioned -- 1 inch = about 2 million years -- evolutionary time line tracing life from first its very first forms to homo sapiens.
Timeline of Evolution - Wikipedia offers a timeline highlighting the emergence of different species over the last 4000 million years.