Yahooligans! Probably the most popular search engine for kids http://www.yahooligans.com
Have a question, just ask Jeeves, and this search engine will look for websites that have your answer. http://www.ajkids.com/
A search engine that was created by librarians. http://sunsite3.berkeley.edu/KidsClick!/
Kids Connect- search for what you are looking for by subject http://www.kidskonnect.com/SubjectIndexHome.html
Tree Search http://www.ces.ncsu.edu/depts/hort/consumer/factsheets/trees-new/common_namesa_c.html
Look up definitions and use the online thesaurus. http://www.m-w.com
nettrekker http://elementary.nettrekker.com/subject/