H.323 Client or NetMeeting Tool
The NetMeeting Client has it's own built in Help.
On-line help for NetMeeting is available from Microsoft NetMeeting.
On-line information on GnomeMeeting may be obtained from GnomeMeeting.
The CD-ROM has a pdf copy of the GnomeMeeting FAQ as faq.pdf in the path /p2p/documentation/gnomemeeting/.