I would personally avoid the word "blog", since it immediately makes me down-rank the book from "ooh, rationality!" to "oh, some blogger feels he's so important he's going to publish an eBook, eeew!"

(Title)The Sequences (Subtitle)Essays on Human Rationality

seems good to me, mostly because I can't think of a better title, but it definitely needs a subtitle to tell me what it is. (I actually like "The Sequences" as a title - it has a bit of an air of mystery, yet also a nice formal, logical sound - it feels like it will teach me something secret, in a coherent manner :))