12 books, 1 per month that includes one or more of the key words for that month. Synonyms and suffixes are allowed. (Theasaurus.com is the final word on whether something is a “valid” synonym.)
January
end, princess, dance, midnight, court, why, winter, story
February
over, edge, rain, blade, red, come, none, glass
March
dear, ink, mercy, fly, lost, never, match, true
April
last, watch, save, garden, girl, sun, tell, tomorrow
May
away, wait, book, rave, lake, angel, island, nine
June
beneath, crown, sing, rule, earth, find, happen, cruel
July
ever, shine, gone, search, wood, under, road, like
August
one, secret, vill, tree, blue, you, flame, thousand
September
country, house, top, man, wild, sweet, once, wake
October
fear, night, silent, wicked, hidden, bones, lied, ghost
November
again, loud, star, stay, air, when, since, race
December
cold, room, life, bell, kiss, dream, until, drink