Past Regents Exams are a great way to prepare for an upcoming regents exam as they provide students with an idea of what to expect.

Additionally, there are numerous online sites that may be beneficial in preparing for the exams.

Regents Review Sites:

Regents Exam Prep - All subject exams

Regents Review Live 2.0 - All subject exams 

US History Regents Review help

Earth Science Regents Review help

Chemistry and Physics Regents Review help

High School Hub