"My new year's resolution is 1136x640" twitter joke.
There are only 3 days left from the first week of the new year, the desire to change something in your life is still warm, but your confidence is falling. It will take a little time and the lists of accomplishments for 2015 will gather dust on a shelf (or in the phone as red badges on the application icon).
To avoid this, I recommend reading a note by Leo Babauta about how to make a new year not look like the previous one.
In addition, a video by Scott Hanselman about productivity, which has collected the experience of many books and practices. Everything is there, and with little waffle. And yes, the guys who work on Windows, have weird slides. Weird slides.
Bonus: Read and watch the video RIGHT NOW. Because if you wait for a specific day to start something, that day is today. And the time is now!