The list will depend on your personal circumstances.
Here's a copy of what was required for my application:
Passports/Travel Documents (Multiple) (required)
Proof of medical exam (required)
Education (diplomas/degrees) (required)
Statutory Declaration of Common Law (IMM5409) (required)
Employment Records (required)
Employment Records 2 (required)
Police Certificates (Multiple) (required)
Proof of Means of Financial Support (required)
Digital photo (required)
Proof of Relationship (required)
Hope this helps!