As the title suggest, I'm very curious about some resources on Napoleonic era tactics and would love to dive into them; however, I'm not sure where to start.
edit: fixed up my wording.
I would recommend looking here, it's the book list I've put together for the Napoleonic Wars, anything by Rothenberg or Chandler is generally good.
On War by Carl von Clausewitz is a famous one, though incomplete but before buying a copy you should probably decide on a translation. Jolles and Howard/Paret are the two most accurate.