I use the mathematical theory of communication in every professional piece of writing I undertake. It underpins every edit to make sure the item remains as effective as possible. It's never let me down.
That said, this isn't an accessible read. There's a lot of maths here (although you don't need to follow it all to understand the basic theory), and if you're aged under 25 the communication terms may seem archaic. Although the terms date, and the numbers can be difficult, the theory itself, whether applied practically or theoretically, is timeless and easily applied to see effective results.
Read the theory, play around with it, and don't be afraid to Google the complicated bits.