I would suggest that you don't do any preliminary reading, and just learn QM directly. There is not much to it, the requisite background is very primitive linear algebra, and Dirac's book "The Principles of Quantum Mechanics" and Feynman's "Lectures on Physics Vol III" can be read with Wikipedia help without any prerequisites.
The classical mechanics you need to know is not very sophisticated either--- you just need to know Newton's laws, and how they come from a Lagrangian or Hamiltonian, which is covered in standard sources. You don't need so much deep stuff, although knowing Poisson brackets is handy for seeing the vestigial quantumness in the classical mechanics structure.
I would suggest reading the following Wikipedia pages for a historical perspective, which helps a lot with historical literature:
This is wrongly left out of most books, and this is a shame. There is no unified presentation of the historical material except on Wikipedia, and this is why these pages are up there. Once you get the historical stuff (it's not a lot), Dirac gives a conceptually self-contained introduction to the mathematics, the notation, and the physics, while Feynman is path-integral friendly, so you can go on to read Feynman and Hibbs, or Mandelstam and Yourgrau without any delay.
It is usually a waste of time to try to go through prerequisites, as these are usually boring and most of the material doesn't end up getting used. For QM, you need to come in knowing what a matrix is, and what an eigenvalue is, which is probably best learned from Dirac.
