Uzas,
Your test letter will mention the documents you need to bring. My test letter instructed me to bring the following items:
1. The test letter
2. Two pieces of personal identification. One with photograph and signature (driver's licence, health card, PR card, etc.)
3. All original documents that support your citizenship application
4. Your ORIGINAL landing paper
5. PR card
6. All passports and travel documents (current and expired)
During the post-test document verification (brief interview), the officer looked at my identifications (driver's licence, health card and PR card), landing paper and passport. She made a copy of my new driver's licence. She went through my passport quickly and compared just a few pages. She asked a few simple questions about my employment and family. Then she said everything looks OK. That was it.
Please note that every interview is different. I saw that some people brought tons of documents with them. In some cases, the officer goes over the passport page by page, and asks many questions.