I’m not much of a linguist in the technical sense, though I do enjoy learning languages (and especially doing translation), so I wasn’t sure if reading a book about invented languages might be too technical. Luckily, it isn’t: In the Land of Invented Languages is actually a really easy read, with a more personal than professional analysis of the languages discussed — although it does go into some details about how each one works, why it’s effective or not, how much it’s used, etc.
Better, Okrent actually participates or participated in some events based around these languages, like Klingon and Esperanto, so she has an insider view (to some extent, anyway). It’s kind of fun reading about how she got hooked on learning Klingon, and her mixed feelings about hanging round with the other Klingon speakers. While she mostly talks about why these invented languages aren’t really successful, she does so with sympathy and an eye to how they create communities and cultures, and also a deep appreciation for the coolness of conlangs and the communities around them. (Even if that coolness is a very geeky, linguistic coolness, obviously.)
It’s an absorbing and entertaining read, which is also pretty informative, and I found myself wanting to share it immediately. For those with a bit more knowledge, I think you might want more detail about the technical workings of some languages, but as a survey of invented languages and their communities, I think it’s pretty awesome.