I've recently dipped my toes into the world of number theory; and I've bought a book that to me is quite unconventional: R. P. Burn, A Pathway into Number Theory. I've yet to put the book through its paces, but it seems agreeable enough to me. The book is unique in that it poses a sequence of questions to you in the hope that you'll be able to answer them and by thus doing so, begin to discover the fundamentals of number theory.
This is a style of learning that I find agreeable as the knowledge I gain this way is assimilated and retained better. I like being able to discover for myself however most times I don't have the necessary direction (I am self-studying) but that's where this textbook comes in. I feel that this book in the process of nudging you in the right direction also helps you think more like a mathematician (from my very limited experience with it).
I enjoy books that give you a "pathway", although I guess this is the aim of all textbooks. Is it possible for anyone to recommend texts that take a similar aided discovery/inquiry based approach?