Hi vinothdhanapal,
first for MoH file addition, the procedure depends on your CCM version, in general for CCM 5.x here is the procedure:
http://www.cisco.com/univercd/cc/td/doc/product/voice/c_callmg/5_0/sys_ad/5_0_4/ccmfeat/fsmoh.htm#wp1027611
and for CCM 4.x here is the procedure:
http://www.cisco.com/univercd/cc/td/doc/product/voice/c_callmg/4_1/sys_ad/4_1_3/ccmfeat/fsmoh.htm#wp1027611
second for the required services: the main service is the IP Voice Media Streaming Service and here is some info:
The Cisco IP Voice Media Streaming application gets installed automatically upon installation of Cisco Unified CallManager. To provide an MOH server, you must use the Cisco Unified CallManager Serviceability application to activate the Cisco IP Voice Media Streaming application.
When a server gets added, the Cisco Unified CallManager automatically adds the media termination point, conference bridge, annunciator, and music on hold devices to the database.
Note During installation, Cisco Unified CallManager installs and configures a default music on hold audio source if one does not exist. Music on hold functionality can proceed by using this default audio source without any other changes.
for CCM 4.x: activate Cisco IP Voice Media Streaming application plus The MoH Audio Translator.
third, you are correct BAT the easiest.
hth
/majdi