Literature (all by Donald Crews, unless noted otherwise):
Freight Train is a classic Caldecott and probably his best well-known work. (Vocabulary: caboose, hopper car, gondola car, tender, steam engine, trestles)
Harbor is packed with vocabulary relating to boats. See the last page of the book for a good picture glossary.
Bicycle Race is good for practicing reading number words. Tricky, though because they're out of order!
Truck, a Caldecott Honor book, at first glance seems like a wordless book, but is full of environmental print. A great way to learn traffic signs (SS K.4.3).
School Bus has a bit more traffic sign-related environmental print and is a great way for my homeschooler to live vicariously through all those lucky bus-riding, public-school kids.
Flying can be used to learn to identify relative location of objects (SS K.4.1). Very readable for new readers. (Vocabulary: taxiing, boarding).
Sail Away uses onomatopoeic words that can give listeners a chance to participate by making the sounds. (Vocabulary: moored/mooring, dinghy, swell, port, lighthouse).
Are We There Yet, Daddy? by Virginia Walters introduces basic map reading skills (SS K.4.2) and counting by tens, but backwards!