Pandora and Youtube will not work

Do you have "block pop-up windows" picked? Go under Safari>Preferences>Security and make sure that option is unchecked. If that doesn't help, go back to Security and make sure the "always" option is checked on "accept cookies."

Pandora, especially, is very fussy when it comes to browsers that don't allow pop-up windows or won't accept all cookies. Especially if you're listening to it for free with commercials. (Just FYI, if you listen to Pandora a lot, you might want to consider become a premium member--cost is something like $36--that allows you to download a desktop "app" so you don't have to keep going to the website to listen to the music. It also frees you from the ads and lets you reject 6 songs per hour).

If all that still fails, quit Safari, go Applications>utilities. Launch Disk Utility and tell it to repair permission. When it's done, re-start the computer. Try again (you can go under History in Safari and have it re-open all closed windows from last session so you get back all tabs and such that you had before if you like). Hope that helps!