I am building a small (2000-3000 records) ACCESS database that
contains names, biographies and a list of publications for female
physicists.  I would like to integrate this database to a small, local
library's online catalog.  Assuming the library catalog is also a
relational database, how would I go about doing this?  Would it be as
simple as matching a key (for example, author last name) between my
ACCESS db and the library db? How would SQL come into play?  How would
I begin?  What are potential difficulties I may have integrating the
data?

Why don't you sent all your data of ACCESS into your local DB. that's
is the perfect solution.

It depends on the local Library DB; what kind of DB is this and also
what kind of application is used on the library to access their
database.

In short:
A database/library application consists of two parts: a) the database,
b) the application that users are using to look into the database.

You would want to do the following.
1. Place your DB at the server where the library DB is
2. Rewrite the library appliation to do a query against your DB too,
based on the seach criteria done agains the library DB. The display
the ressult from the library DB and your DB

OR
1. Import your data into the library DB. If the library DB is a MS SQL
database, it would be easy using DTS

OR
1. Make availible your Access DB to the library computer users. Then
they could search the library DB trough the library application and
also search your DB trough opening a form from your MS Access DB

OR.....
there is a lot of way to do this. It all depends on what access you
have tho the library server/computer, what access you have to the
library applications source code, what access you have to the library
DB itself etc etc.