I've taught a similar course. I used Lightman's Great Ideas in Physics (4
sections, two of which are on relativity and quantum mechanics; the other
two are on conservation laws and the second law of thermodynamics - I
covered the entire course in a semester). I don't know if his sections on
relativity and quantum are enough for a whole semester. I supplemented with
Feynman, the Cartoon Guide to Physics, and miscellaneous.
--
regards
-Krishna
Krishna Chowdary
Department of Physics & Astronomy
Bucknell University