Royal Signals do a very good self teach pam called ARMY ORGANISATION AND
MILITARY MAP SYMBOLS (tdtmod1.pdf), its available on the TDT CD (which all TA signals should have)
BTW this is basic signals knowledge that all trades should know (any prospective class 1 operators should also be given the CD I mentioned above as it contains all the pams needed for the pre course entrance test)
I would add to the site but it is restricted and once again ArmyNet shows how usefull it is by not including them on the SOinC's community.
This sort of information should be learned and not stored in a orders book