Library of Congress
Loc: Nation Expansion and Reform: Traveling on the Overland Trails, 1843 1860
Primary source information about traveling the Overland Trails, both to Oregon Country and California.
Sacramento Bee
Sac Bee: The Journey by Land
This CalGoldRush.com site discusses where people came from and the many routes that were taken to get to California. Many traveled the Mormon and Oregon Trails.
Other
Overland Trail: Concord Coach
Check out all the links here to gain fascinating insight into what it would have been like to travel west by stagecoach in the late 19th century.
Curated OER
National Park Service: California National Historic Trail
This site from the National Parks Service gives a brief history, and description of the California trail system which was used by settlers moving to California during the 1849 Gold Rush days.
Other
Overland Trail: Overland Trail Stage Stations
Description of the stations that were established every 10 to 15 miles or so along the Overland Trail. Hyperlinks to much additional information.