Access Programming Skills Improvement

I need a recommendation for how I might improve my Access development
skills (and ultimately, my code) given my personal profile below:

Years Programming (in any language/environment): 18
Years Programming in Access: 5
Self Assessment of Access Programming Knowledge/Skill Level (Novice,
Intermediate, Expert): Low Intermediate using VBA code in forms, and
using Access macros
Some Current Challenges: Importing comma-separated-values files into
existing Access tables WITHOUT duplicating existing records;  
Allowing users to access their data in a way that protects the
integrity of the data (their data would be "read only") and also
allows me to "disconnect" the users or otherwise regain control of the
.mdb file (or the xxx_be.mdb file if I split the data out
separately--which I've done before) so that I might move or delete it
in a Windows NT environment (I've tried data access pages but with
some apparent file locking problems)

I am open to the following means of learning how to do these, and many
other, things within Access:

* Books (including code samples)
* Classes
* Videotapes
* CD-ROMs
* On-site Coaching/Intensive Tutoring

Thanks for any suggestions.

Keith