I'm a business/international relations person and a lot of my job is flying around. I have had a lot of downtime recently, and couldn't find a sustainable hobby to fill in that time.
Until I found Michael Spivak's Calculus and decided that it was legitimately a very fun book to read. I didn't actually do the problem sets, but I read the book carefully, and can say that while I by no means mastered the material, I'm generally conversant in it. I might actually end up doing the problem sets at some point, but that's another thing...
In a similar vein to my previous endeavors, becoming "fluent" in undergraduate biology and philosophy through self-study during my downtime, I'd like to do the same thing with mathematics and statistics.
Can someone help me plan out and structure what books I should read and in what order? Let's try to avoid popular science books. I liked the level of technicality in Spivak's book. Again, I'm not trying to reach any sort of academic mastery, just technical "conversational" fluency.
There are plenty of "what should I read" questions around, but I think mine is slightly different, by virtue of asking for a structure, and specifying what I want to achieve. Also, I like the proof-based approach used by Spivak, and would like to see something similar for statistics.
edit
To clarify, when I read Spivak's book Calculus, I didn't skip the dense parts. I read and understood the proofs. Whether I could replicate them on my own is another issue--I attribute this to the lack of problem sets completed--but I enjoyed the dense parts of Spivak's books. So, I am absolutely looking for something more technical than A Brief History of Time, etc, etc.
It looks a bit like you'd like some advice on texts for topics. I think you would get maximum benifit from those if you did the problems. If you aren't going to do problems, I'm thinking I should recommend some general reading on math rather than texts.
If you want a big general reference, I imagine that the Princeton Companion to Mathematics would suit you well.
If you wanted to get a kind of casual blanket knowledge about what different flavors exist in mathematics, there are quite a few "popular" reading books you could look at.
If you have any interest in physics, I could recommend Penrose's "The Road To Reality". The first half is chock full of a lot of mathematical ideas and general discussion of them. Dense parts can be skipped over without any problem.
I also remembered Paulos' "Innumeracy" being good (but I didn't really enjoy his " Mathematician reads a newspaper" book.)
While I haven't had time to read it, I imagine Hofstadter's "Godel, Escher, Bach" would have an interesting perspective of some math ideas.
There are a lot of things like "50 math ideas you need to know" that would make good plane reading too, I imagine (without having read them.)
It sounds like you aren't as interested in problem solving, but if you ever did want to try your hand at mathematical puzzles you would pick up any of Martin Gardner's books on math puzzles. Great for planes!
Edit It sounds like you were serious about doing problems, so I'll have to add some texts!
Kelley's General Topology
Stein and Shakarchi's Analysis book
Anderson and Fuller's Rings and Categories of Modules
By the way, the Road to Reality mentioned far above contains lots of exercises!