Sue,

The two-volume Modern Library edition of Twain's work,  MARK TWAIN: TALES,
SKETCHES, SPEECHES, AND ESSAYS, edited by Louis Budd, is a goldmine. See
"Miss Clapp's School," "Advice for Good Little Boys" and "Advice to Good
Little Girls" in the same volume; or "Colloquy Between a Slum Child and a
Moral Mentor." There are too many to list. The two volumes cover 1852- 1910.
Mark Twain's autobiography is another great source--there are several
editions. Charles Neider's may be the most widely available. Oh, before I
forget: his essay on Harriet Shelley reveals a side of Samuel Clemens (I
think he signed it "Samuel Clemens") that we don't often see. It was
published around 1890, I believe, in one of the high-brow journals. A few
scholarly treatments have been published in the past decade or so, too; see
Gregg Camfield's SENTIMENTAL TWAIN.

Didn't he also write something about the mores or the manners of the
Elizabethans? I can't recall the title at the moment.

Barbara Ladd