ldap schema

[slyle@plasticmoldings.com]

What is the easy way / resources you know of to come up to speed on ldap 
schema?

I'm not finding a whole lo of support for understanding schema except to 
read the schema files.
Even then they are rather cryptic and difficult to relate to in functional 
/ actionable / practical information.

There seems to be even less error trapping & reporting support from ldap 
when ldapadd parses a ldif file.
For example: I attempted to import:
---
dn: uid=bbonzai,ou=People,dc=pmc
objectClass: top
objectClass: account
objectClass: posixAccount
objectClass: shadowAccount
cn: Buckaroo Bonzai
uid: bbonzai
uidNumber: 11000
gidNumber: 11000
homeDirectory: /home/bbonzai
loginShell: /bin/bash
gecos: Buckaroo Bonzai,Bonzai Labs 101,888-555-1234,555-4321
userPassword: {crypt}x
shadowLastChange: 0
shadowMax: 0
shadowWarning: 0
---
and got this error
---
ldap_add: Invalid syntax (21)
        additional info: objectClass: value #1 invalid per syntax
---
Which of the four objectClasses above are in error?
Which schema of the five default (from the slapd.conf included in the 
installation of version 2.2.28) is being used to define the syntax so I 
can lookup the correct schema?