Not a native speaker either but it seems like an acceptable sentence. Here is a slightly reworked version that might be easier to understand. The brackets mark

Not a native speaker either but it seems like an acceptable sentence. Here is a slightly reworked version that might be easier to understand. The brackets mark where I added something or left something out: "I am sure that many [...] readers of this [...] book know [the book] 'On the Origin of Species' (by Charles Darwin) inside and out." Edit: "to know something inside and out" means to be very familiar with something.