Nature's Paintbox: A Seasonal Gallery of Art and Verse by Patricia Thomas, illustrated by Craig Orback is a new favorite of mine.
"How would you capture winter's crispness, spring's softness, summer's freshness, and autumn's richness? In this inspiring picture book, poet Patricia Thomas imagines each season rendered in a different art medium. Pen and ink, with spots of color, capture winter's mood, while pastel chalks make spring flowers bloom into life. The see-through hues of watercolors celebrate summer's warmth, while vibrant oils perfectly pain fall's majestic scenes. Artist Craig Orback takes up the poem's challenge in his marvelous illustrations, using each of the mediums described. Just as the seasons move seamlessly into one another, so too do the art styles blend together, then emerge in full splendor, and blend again as the next season approaches" (from the inside jacket).