His brief Wikipedia entry is here. A more personal appraisal by Jim Vadeboncoeur Jr. is here, and a Muddy Colors post about him by Greg Ruth is here.
Coll produced a huge amount of illustrations during his comparatively short career, so there naturally was variation in quality. Below I present a collection of what I consider his better work. Most of his illustrations were vignettes or non-framed full-page illustrations with plenty of white space. When he did framed illustrations or illustrations of night scenes, the results were usually murky looking -- an effect hard to avoid given his preferred medium.