This article is from the RSC/UKSC Cricket FAQ, by Ganesh with numerous contributions by others.
_Tom Smith's Cricket Umpiring and Scoring_ will
tell you all you need to know. ISBN 0-297-64604-4
If mail-order from England is your best bet, check out
This is the ONLY book recognised by the ACU&S. As
such, it is not only 'the bible' but the textbook on
the subject. The ISBN number probably changes with each
new edition - yearly ?
Alan R Tuffery:
The following little book [is also] useful.
There is a webpage about I'll try to find the URL.
Hibbs, Derek, (1994). Cricket Scoring, A Handbook
for Scorers in Club Cricket. From the author, 1
Cleevelands Avenue, Cheltenham GL50 4PY (lbs 2.95
+ 0.30 p&p in UK)