Yes. Please use the search function.
http://au.toyotaownersclub.com/forums/topic/51464-thermo-fan-forced-on-manually/
http://au.toyotaownersclub.com/forums/topic/18782-for-those-with-an-ignition-key-barrel/
Overdrive, leave it on in most cases, it is basically another gear. It helps with fuel efficiency(lowering RPMs) and transmission life. It can be turned off to assist with steep hills.