Here are links to some great websites:
Seventy-Five Years in California by William Heath Davis. The entire text of this rich memoir of life in California in the 1800’s is available for free on the Library of Congress’ American Memory webpage.
Web de Anza provides students and scholars with primary source documents and multimedia resources covering Juan Bautista de Anza’s two overland expeditions from the Sonoran desert to northern California, leading to the colonization of San Francisco in 1776.
Saving the Bay has some great videos portraying the first European encounters with the San Francisco Bay, including the Portola Expedition, the Anza Expedition, and Juan de Ayala’s first ship entry through Golden Gate.