Also look inthe WmEDISamples package xmltoedi,editoxml folder services, this package comes with EDIModule6.x i,it gives a good start in mapping,utilizes edi builtin services (WmEDI,WmEDIForTN packages) and ofcourse read the EDI userguides,visit ediuniversity.com for basics.
HTH,
RMG
#Integration-Server-and-ESB#edi#webMethods