This is the 2353rd most frequent Russian word.
немало
"Немало" means "quite a lot" or "a significant amount."
Here, 'немало' means 'quite a few' or 'a good amount,' indicating a significant quantity of books that the person has read.
Он прочитал немало интересных книг.
He has read quite a few interesting books.
In this sentence, 'немало' signifies 'considerable' or 'a substantial amount,' referring to the effort needed for success.
Для успеха в этой работе потребуется немало усилий.
Achieving success in this job will require considerable effort.
Here, 'немало' reflects the meaning of 'quite a few' or 'several,' emphasizing the number of hardships experienced.