Read textbooks in the subjects of the courses you will be taking.

Robin Hanson recently quoted this book. It summarizes the most effective learning strategies (and was written by a pair of cognitive scientists who just spent a decade studying optimal learning). It should come with a disclaimer that (contrary to what most people will tell you), college isn't about learning, so if you just go there to learn but not jump through the other hoops, things will end badly (relevant Quora answer, SMBC, lecture; the lecture is imperfect, but still valuable).

I also found HPMOR useful when I was in college.

I also recommend either C.S. Lewis's The Screwtape Letters or The Great Divorce. Both are compelling portraits of the ways we humans tend to make ourselves unhappy by becoming enraptured with and enslaved to lesser goods. I mean, can you ask for a better portrait of akrasia than this?

As the uneasiness and reluctance to face it cut him off more and more from all real happiness, and as habit renders the pleasures the vanity and excitement and flippancy at once less pleasant and harder to forgo...you will find that anything or nothing is sufficient to attract his wandering attention. You no longer need a good book, which he really likes, to keep him from his prayers or his work or his sleep; a column of advertisements in yesterday's paper will do. You can make him waste his time not only in conversation he enjoys with people whom he likes, but also in conversations with those he cares nothing about, on subjects that bore him. You can make him do nothing at all for long periods. You can keep him up late at night, not roistering, but staring at a dead fire in a cold room. All the healthy and outgoing activities which we want him to avoid can be inhibited and nothing given in return, so that at last he may say...'I now see that I spent most my life doing in doing neither what I ought nor what I liked.

Obviously these books were written from a Christian perspective, but I found them really helpful for noticing bad patterns in my life (and small ways to break out of them) when I was an atheist. Lewis is a vivid writer, so his stories gave me good handles for noticing when I was in one of the ruts he describes, rather than just feeling a general, ugh-y malaise.

Don't Shoot the Dog is one of those few popular nonfiction books I've read that seemed to pack a decent amount of novel info on to most of its pages. There's more to training people and animals than just what Lukeprog summarizes.

Scott Adams' self-help book received a glowing review on LW. I'm enjoying the book so far; it is also pretty info-dense, but a lot of the ideas were ones I had heard previously or come up with on my own (likely not true for most people).

Overall though, I think books are overrated. Many of them have about as much quality info as a good <20 minute TED talk or a solid 15-page blog post. I assume that's because authors are pressured to inflate whatever they're trying to say until it reaches at least "book length" (~100 pages).

You already mentioned the one I would recommend, Getting Things Done. GTD is a great system for college students keeping on top of their work while still making time for fun.