  We study k-Schur functions characterized by k-tableaux, proving combinatorial
properties such as a k-Pieri rule and a k-conjugation. This new approach relies
on developing the theory of k-tableaux, and includes the introduction of a
weight-permuting involution on these tableaux that generalizes the Bender-Knuth
involution. This work lays the groundwork needed to prove that the set of
k-Schur Littlewood-Richardson coefficients contains the 3-point Gromov-Witten
invariants; structure constants for the quantum cohomology ring.
