Reddit mentions of The Winter Solstice

There is not much available in terms of atheistic picture books at all, and I can't think of anything for a 2-5 year old. I'd say some books on mythology (to get them started recognizing it), or astronomy, or dinosaurs, whatever's well reviewed in those areas, could be appropriate. Once you're into the 6 to 8 yo range, there are a few more picture books:

http://www.amazon.com/gp/product/1578840163/ref=ox_sc_act_title_1?ie=UTF8&m=ATVPDKIKX0DER

http://www.amazon.com/Winter-Solstice-Ellen-Jackson/dp/0761302972/ref=sr_1_1?ie=UTF8&qid=1323733377&sr=8-1

http://www.amazon.com/Stones-Bones-Char-Matejovsky/dp/1598150049/ref=sr_1_1?s=books&ie=UTF8&qid=1323733624&sr=1-1

http://www.prometheusbooks.com/index.php?main_page=index&cPath=96&zenid=s4591gebo9q6ardl0ur6a57992