I'd agree with L. Spiro though: if you've really just read through the book you need to do some actual programming -- there's absolutely no substitute for real experience. Work through any exercises provided, and experiment with writing small programs, intentionally causing errors, etc. to learn as much as possible, and if you feel like you need to perhaps look at additional books.
Once you feel you're ready to try tackling a game, you'll want to choose and learn an API that provides windowing, graphics, input handling, etc. One such popular choice is SDL, using Lazy Foo's tutorials to get started, but SFML or Allegro are also very popular and capable choices.
Set yourself a goal of some simple game to make -- I normally suggest "Pong" as a first game -- and set about breaking it down into smaller tasks you can approach one at a time. For the example of Pong, a starting set of goals might be:
- Learn to create a window.
- Learn to draw a rectangle (which you will eventually use as the player's paddle).
- Learn to move your rectangle in response to player input...
- ...and so on and so forth...
//EDIT: It's absolutely worth spending the time to try some simple text-based games before moving on to graphics as others have suggested. This is a relevant goal (you get to make some playable games) but can really help to solidify your knowledge before moving on to more complex topics. Only you can decide when you want to move on however, and you can always come back to the basics if you find things too difficult.
Does that help?