More likely your second because most men have their first one in their 20s, when adulthood turns out to be not at all like what you expected.
Rather than fish for books, I'd recommend having a look around at your friends, workmates, and acquaintances about your age or a little older and identify three things:
1. Who is having the most fun?
2. Who has reasonable job security, to the extent that exists today?
3. What skills do they have that you don't?
Use these things to guide your choices for skills to develop- maybe they are technical, or maybe they are people skills, but you'll be working towards filling a deficit that can open new/better opportunities for you.
Personally, I think there is limited benefit to enhancing coding skills, such as learning a new language or framework- they are a dime a dozen and the industry always has a new fad. On the other hand I think there's a lot of value in learning new analytical skills. Everyone and their dog wants to mine actionable intelligence from their customer data and the ability to scrub, synthesize and model is a key asset. Plus when the data is sufficiently rich it can be a lot of fun compared to setting up yet another web site. If you want to take it all the way to home plate, pick up some machine learning skills, eg by taking one of the Stanford or Udacity online courses and dazzle your employers with your ability to predict that your customer is pregnant... ;-)
btw, IMO a promo every three years seems about par for the course- not fantastic but nothing to complain about. The real difficulty is that promotion velocity tends to slow over time, since there can only be so many head chefs.