Here are two books that I'd recommend for the practicing thermal engineer in electronics packagaging, both by Tony Kordyban:
Hot Air Rises and Heat Sinks
More Hot Air
Both books are extremely useful for all the practical, hands on experience that Mr. Kordyban has gained over his years in electronic packaging. Also, the books are very entertaining, being full of humorous stories about learning from others' mistakes and how people use their supposed common sense to solve heat-transer problems but get everything all wrong anyway.