I found Joshua Foer's book Moonwalking with Einstein both enjoyable and edifying. It combined practical advice about having a better memory with useful tutorials on its neural basis and some interesting cases of memory loss with entertaining tales about professional memory competitors. In particular, I found the discussion of memory palaces from the time of the Greeks on particularly useful and an easy method to remember things better. (However, I found a number of the other techniques such as associating pictures with digits a little harder to practically use and wish there was a bit more of a tutorial on them.) The discussion of the famous memory-loss patients such as HM was fascinating and I found the author's discussion of how he tried to participate in memory competitions quite interesting both for his realism about a lot of the practitioners and also his personal snippets of what it was like. In relation to this, at the end of the book there is an interesting episode where he suggests that a famous case of extreme "natural" memory (Daniel Tammet, autistic savant) is actually a memory competitor hiding his technique.
Overall, a good read that I would recommend though I wish there was a little bit more detail on how to actually get a better memory and a little more on the neuroscience.
Moonwalking with Einstein: The Art and Science of Remembering Everything
By Joshua Foer (2011)