Useful Oracle Reference Manuals

Oracle Database 2 Day DBA 10g Release 2 (10.2) B14196-01
Oracle Database Administrator's Guide 10g Release 2 (10.2) B14231-01
Oracle Database Backup and Recovery Basics 10g Release 2 (10.2) B14192-01
Oracle Database Concepts 10g Release 2 (10.2) B14220-01
Oracle Database Licensing Information 10g Release 2 (10.2) B14199-01
Oracle Database Net Services Administrator's Guide 10g Release 2 (10.2) B14212-01
Oracle Database Net Services Reference 10g Release 2 (10.2) B14213-01
Oracle Database New Features Guide 10g Release 2 (10.2) B14214-01
Oracle Database Performance Tuning Guide 10g Release 2 (10.2) B14211-01
Oracle Database PL/SQL Packages and Types Reference 10g Release 2 (10.2) B14258-01
Oracle Database PL/SQL User's Guide and Reference 10g Release 2 (10.2) B14261-01
Oracle Database Recovery Manager Quick Start Guide 10g Release 2 (10.2) B14193-01
Oracle Database Recovery Manager Reference 10g Release 2 (10.2) B14194-01
Oracle Database Security Guide 10g Release 2 (10.2) B14266-01
Oracle Database SQL Quick Reference 10g Release 2 (10.2) B14195-01
Oracle Database SQL Reference 10g Release 2 (10.2) B14200-01
Oracle Streams Advanced Queuing User’s Guide and Reference B14257-01
Oracle Streams Concepts and Administration B14229-01

This all can be downloaded from oracle's official website http://www.oracle.com/