We can't think of an electron as being just like a scaled down version of, say, a billiard ball, in the sense that we can't say that it has a position or has a motion until we've actually measured either its position or its motion. In the absence of a measurement, we can't say that it has either of these qualities.
Reading
R. Peierls, interviewed in P.C.W. Davies and J.R.Brown (eds.), The Ghost in the Atom, (1986), pp. 70-82.
Bernard d'Espagnat, `The Quantum Theory and Reality' Scientific American (1979), pp.128-140
P.C.W. Davies and John Gribbin, The Matter Myth (1991), pp.191-228
John Gribbin, `The Man who Proved Einstein was Wrong', New Scientist, 1990.
J. Powers, Philosophy and the New Physics, (1982), pp.124-164.
`Aspects of Light', The Economist series Tests of the Truth: The Experiment in Modern Science (1993), pp.20-21.
Reading
Michael Redhead, Incompleteness, Nonlocality and Realism (1987), pp.71-118.
Arthur Fine, The Shaky Game (1986), pp.26-63.
Albert Einstein, `A Letter [to Karl Popper] from Albert Einstein' in Karl Popper, The Logic of Scientific Discovery (1959 -- originally published in German in 1934), pp.457-460. I've also included pp.236-246 in which Popper describes his `imaginary experiment' which Einstein criticizes.
Abner Shimony, `Conceptual Foundations of Quantum Mechanics' in Paul Davies (ed.), The New Physics (1989),pp.373-395. [Read this only if your maths is good, and you know some vector algebra.]
All of the above readings are in Mrs. Lau's xerox collection, available on 2-hour loan in the Department of Philosophy. I have also included, for those who are interested, The Feynman Lectures on Physics : Quantum Mechanics §§ 1.1 - 2.2.