there is no redemption period for foreclosures. However, if you buy pre-foreclosure there is some statue limits of 2 yrs. with respect to reversal of sale, etc
you might consdier to spend some time at www.foreclosureforum.com (lots of CA foreclosure guys posting there).
also, be sure to read the section of codes (look on the left side) section 1695 and 2927 are pretty important if you going to be involved in preforeclosure buying