Titration is part of the HSC course in the topic called "The Acidic Environment". So pick up any HSC Chemistry text book and they should have a summary of the procedure
Chemistry Olympiad - Does your school offer olympiad training? If they do, join that! If not, ask your teacher or the science department for appropriate material, and they may keep past olympiad papers.
RACI - Same with insert-username I've also been a recipient of the Excellence Award. No study is required. Though if you want to excel in this competition you can brush up on the chemistry concepts that you have been taught at school. Again, you may ask your teacher for past papers if you find it necessary.
Hope it helps!