Researchers read many books should be considered ok...
Cercetători would be "Researchers read many books..." Cercetătorii is the correct translation since there are two i's on the end.
Literally taken you are right but I think Romanian requires some specification here (the definite article, or niște) while English does not.
Not using the definite article in English makes the statement a general one. Try to avoid translating word by word.
Sorry but "many" is the same as "a lot of".