The most recent NCTM(National Council of Teachers of Mathematics) newsletter
some information on block scheduling -- it also lists several WEB sites for
information on block scheduling.
I forgot who had the question about it, but if you e-mail me I will get the
info to you.
Also, there are many different ways to arrange block scheduling - I would
love to have two hour blocks for my art and math classes, especially if I
could have them everyday! Some schools arange it by semester, others have a
M-W, T-Th, alternating Friday schedule, or have all classes for a shorter
period of time on Friday.