The second guy probably did you a favor. Often the "best" trails in any given area are kind of "grey area", if not downright illegal. Sad but true. If too many people find out about them they become over crowded, land owners/managers find out about them and they are destroyed. So if he'd told you about them he'd hafta kill ya

Don't you find that the singletrack you "discover" on your own is just that much sweeter anyways?

If you are looking for "established" trails (legal) you might try asking at the nearest bike shop or local club.