YouTube is like a massive public library: Random browsing can be overwhelming. To make your visit effective, you need to have some inkling of what you want to watch and how to find it. The finding isn’t hard: You type in the name or info, as you would on any internet browser, then either choose from what the site surfaces or refine your search terms. As for what to watch, use your imagination. Any movies, concerts, old shows, topics or how-tos come to mind? YouTube has built up an impressive library of rotating longform video content, from TV’s The Dick Van Dyke Show to movies like Moonstruck and The African Queen. There are also listings out there; for example, each month, Rotten Tomatoes posts 100 free YouTube movies currently available. Or you can follow your passions: A search on “Miles Davis full concert,” for example, brings up several archival jazz concerts from the 1960s onward.