Paging /u/davidaop

For the average age question - the closest way to get an answer right now is the work of Marcus Rediker in his book, Villains of All Nations, which surveyed some 900 sailors during the 1713-1726 period. For the pirates that had age data on them, Rediker concluded an average age in the late 20s. Some have discussed the potential biases in this data - but if you want to take anything away from it, remember that pirates were mostly sailors, and that the maritime service was a young man's game (plenty of teen, especially late teens, and 20s), and it's leaders/officers were often in their later 20s, 30s, maybe 40s. Hope that helps you on that, and if you want more on the age stuff, go look up that book.

As for the other thing, "what can you tell me about pirates" - extremely broad question. You might want to 1) check out the AskHistorians Reddit FAQ section on pirate history (click here) and 2) Check out my blog posts on pirate history, the "Colonies, Ships, and Pirates" (click here) blog, where I have a few posts on pirate history and there will be others in the future. If you're doing research, you might want to check out the Recommended Books on Pirate History (click here) I have there.