Perturbation theory is a quite technical subject, and if this book can explain it clearly and with ease this sounds like a real find. Goswami has a good discussion on variational methods and building trial wavefunctions (although it's brief).
Books and authors are always a matter of opinion. I've been tutoring undergrads in quantum mechanics for about ten years now, and the students I've worked with couldn't relate at all to Walter Thirring. They said the book was too bogged down in math and formalism to get a clear "rudimentary"...
I need to runs this by some others to make sure it checks out. The guy that runs bugsweeps.com claims that microwaved food is dangerous. He claims that the water molecules in the food keep oscillating at 2450 MHz after the food is removed from the oven and this is somehow dangerous to us. So...
Quantum Mechanics Self-Study
If you are trying to study quantum mechanics on your own (which is commendable and shows ambition on your part) I would recommend that you get Amit Goswami's book. It is written on the level for advanced undergrads and beginning grad students. Some will say...