Former sites InternetPublicLibrary and Librarians' Index to the Internet have combined to form ipl2. This link takes you to the Kids' section. There are a wealth of resources here (over 340 in the Reading Zone alone), and even an opportunity for students to ask for assistance via email.
Free tool that lets you input TEDTalk or academic paper; gives you links to related research. Could be very useful for students doing research on a particular topic