it took me a while as I've failed before previously.
But anyway, it took me 3 months of study. and I used the following:
1) CISA Certified Information Systems Auditor Study Guide by David L. Cannon (Paperback - Mar 24, 2008)
2) CISA Practice Question Database v9 English Edition
3) CISA Review Questions, Answers & Explanations Manual 2009 Supplement (100 questionnaires)
I did not use the 2009 Review Manual as it's just too many "old stories" inside. that's why I just used the study guide by David L. Cannon.
this year I'm going for CISM/CISSP, after that, I think that's all for the paper collection.