Math and physics enthusiasts looking to refresh their knowledge after a long hiatus can find useful resources online. Khan Academy is mentioned as a tool for practice problems and review, though some users criticize it for being superficial and recommend it only as a supplementary resource. For a more in-depth study, textbooks like "Basic Mathematics" by Serge Lang and the "Forgotten" series are suggested, with the latter being noted for its affordability. Users also discuss the need for a graphing calculator, with the TI-89 being a popular choice, although its acceptance varies by institution. The TI-83/84 series is often recommended for students due to its compatibility with school policies. Overall, a combination of online resources, textbooks, and appropriate calculators can effectively aid in brushing up on math and physics skills.