Sumner Stone is publishing some very interesting articles on type & letterforms history and practice in his "Alphanet Journal" online. I have found the latter two of particular interest:

http://www.stonetypefoundry.com/warpwoof1.html

http://www.stonetypefoundry.com/letterslost1.html

One of the most interesting facet in both writings is Stone's growing concern towards pre-Roman letter shapes, an unlikely approach in today's typography, I guess.