Regardless of what most usage books say, it might help you to better understand the distinction if you're mindful of the following points:
(1) It's all about the meaning. What "some"/"any" means is all that matters. "Some" means something limited in the context, whereas "any" emphasizes that there's no such limitation. For example, by "some information" you mean "a limited set of information given the context." By "any information", you mean "an unlimited set of information given the context."
(2) Generally, you have a limited set of information. Hence, "I have some information about the car accident." If, however, you'd like to emphasize that you know all about the car accident, you might be able to say, contrary to most usage books, "I have any information about the car accident", although the usual context makes it very unlikely.
(3) The difference between "Do you have any/some information about the next class?" is that you normally use "some" here for the context-specific limited set of information, and that you may well use "any" instead in order to emphasize that you're not limiting the type of information about the next class.