Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. They tackle math, science, computer programming, history, art history, economics, and more. They've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content.

Free online help with schoolwork from expert tutors with a Sacramento Public Library card. Available seven days a week from 1 p.m. to 11 p.m. Follow hyperlink to the saclibrary.org and click on Teens at the top. Then click on the Homework Help box. Enter your Sacramento Public Library card number. Then type in your homework question for the online tutor. Services available: help with all subjects, grades K-12, as well as some college and advanced courses; reading and other skill-building assistance; and a writing lab, with writing and composition feedback returned within 24 hours. Sacramento Public Library cards are free at your local branch!

Zotero collects all your online research in one single, searchable place. You can add website bookmarks, PDFs, images, audio and video files, snapshots of web pages, and really anything else. You can also create MLA citations of websites to use in a bibliography, access your account from any computer, and share links with friends.

Research and citation resources from Perdue University.