For a decent introduction to theories of information and information flow, with a focus on semantic information and approaches from within philosophy, I recommend Information and Information Flow: An Introduction. Authored by Manuel Bremer and Daniel Cohnitz, it is based on a series of lectures they gave some years ago.
When I first started looking at information, I found this book to be very helpful and informative. One issue I have with the book though is that it seems to have been put together a little too hastily and as a result is somewhere in between a collection of lecture notes and a refined, replete book. Primarily it suffers from some inadequate explanations and some awkward material flow.