I second the comment that you'll be best off in the long run with DBI and that DBD::SQLite is a good choice if you aren't ready for a full powered database system. If you can get by with something even liter or if you already have data in DBM formats, then <shameless plug> try my new DBD::DBM. It handles all formats of DBM, is faster than SQLite for many simple operations., and is as lightweight as they come - just install DBI version 1.42 or higher - DBD::DBM comes with it.

DBD::DBM can work with BerkeleyDB and MLDBM and both of those are also handy on their own. See also the pod for AnyDBM_File for a brief comparison of different DBM types.