If you are talking about turn-based chess, then no, this is not cheating. The rules state "You may NOT get any help from any person or any chess engine that analyzes your specific position, including tablebases. You MAY use books, magazines, or other articles. You may also use computer databases (including Chess.com's Game Explorer)."
If you are playing Live Chess, any type of assistance at all is cheating.
Do you consider it cheating to use a book to help u in a tournament, with openings u are not familiar with?