The smbmount in the previous command sets the permissions so that only root has write access to the share. The following command sets some additional information to give members of a certain group (wheel in this case) read/write to the share, while forbidding any access to users who are not members of wheel.

(All this should be on one line)
mount -t smbfs -o username=NTUserName,workgroup=NTDomainName,gid=wheel,rw,dmask=770,fmask=770
//NTServerName/ShareName /mnt/MountPoint