Would a professional researcher use kiddie stuff to write their report?
Right! Professional researchers use the best sources available. You cannot produce a good essay unless you do good quality research. Encyclopaedias can be useful as general introductions to your topic area but once you have a feel for the topic, leave them alone. Go to the experts. These can be found in books by reputable publishers and in journal articles. Read as widely as possible, too. That way, you can compare your sources and will be able to read them more critically.