Often times they don't know why they want to go on line. When they've exhausted those sources and have a good idea what their topic is all about, I let them go on line. Adults too aren't off the hook. They too should have some idea of what they want and what they're looking for before going on line. Or try the address at another time.
Sites do go down for routine maintenance.
Sometimes they're busy. And sometimes you can't connect because they're no longer in service. Once it's bookmarked, just call it up address from your bookmark file instead of typing it in. This saves a lot of time especially when it's a long address. Use a notebook to bookmark your favorite sites and e-mail addresses on paper as well.