There were none available for those two subjects when I sat my PPL exams in 2003. Flight planning was mostly common sense and most of it you would have picked up from other subjects and your practical flying. I did that exam last and scraped a pass by doing no work for it.
Helicopter technical (as opposed to Principles of Flight I assume) is type specific so all you can do is thoroughly read the manuals.
Cheers
Whirls