For a really substantial and comprehensive Twain biography (the first in a
long time of Twain's entire life ... many of your respondents have already
noted that the best-to-date contemporary bio is of only half his life) I'm
looking to the new one by Fred Kaplan, whose Charles Dickens and Henry James
are considered the definitive one-volume biographies of our time.   I
certainly anticipate he'll do the same for Mark Twain.   Last I heard, it is
due to be published -- by Doubleday, I think -- next year.     Lydia