Oracle 10g DBA Exams

1z0-040    Oracle Database 10g: New Features for Administrators
1z0-045    Oracle Database 10g: New Features for Oracle8i OCPs
1z0-042    Oracle Database 10g: Administration I
1z0-043    Oracle Database 10g: Administration II
1z0-041    Oracle Database 10g: DBA Assessment
1z0-048    Oracle Database 10g R2: Administering RAC
1z0-312    Oracle Application Server 10g:Administration II
1z0-046    Oracle Datebase 10g: Managing Oracle on Linux for DBAs
1z0-051    Oracle Database: SQL Fundamentals I

Guideline link:

http://www.orafaq.com/wiki/Certification_FAQ
Oracle Certifications – All
Oracle Certification Program
10 steps of Certification