I don’t know of a single poet with a forthcoming book who hasn’t agonized over cover design and how to find a good designer. I just stumbled on The Book Cover Archive, a site that’s a goldmine of ideas and portfolios of designers, as well as books on cover art. They say cover design is one of the big factors in book sales — don’t know it anyone has stats to prove it — but it’s certainly a big factor in author confidence.