I highly recommend Frederick Lewis Allen's 1931 classic Only Yesterday. It reminds me of the decade retrospectives (1960s, 70s, etc,) that CNN has - but Lewis wrote his classic long before CNN. Even by 1931 - in the wake of the Crash and so many other profound changes, the 1920s seemed like another time. Lewis speaks as a first-hand observer to other first-hand observers, but because of change, he also writes with a certain amount of historical perspective. It's a great place to start, to understand everyday life.

My copy - which dates to the late 1930s - was given to me by one of my professors who was born in 1920; he valued the resource, and when I first expressed an interest in knowing more about the 1920s, he gave me his copy.

Lewis wrote a sequel about the 1930s, Since Yesterday, which first appeared in 1939, intending to capitalize on the success of the original. It's very good as well, but "Only Yesterday" is a classic. (My professor gave me that copy as well; he also gave me my first-edition Oxford English Dictionary - all five feet! It's always a good idea to befriend old professors who are about to retire!!!).