I remember really liking the conlang book too, though I did feel it glossed over a lot of stuff -- though I assumed it was because I was pretty familiar with the subject.

(Also Esperanto culture is pretty fun -- I don't know if they still do this, but maybe twenty years ago they had summer courses that people would come from all over to attend, and one year it was where I grew up. So I spent a summer when I was 15 learning Esperanto and going to Esperanto parties.)