You may want to start with our own extensive article on Sleep and Adoption ...
This book bridges the gap between "attachment parenting" approaches and "sleep training books" nicely, showing that it's actually an artificial divide. Highly recommended for babies/toddlers/preschoolers.
This is my one of my favorite sleep books. Mary Sheedy Kurcinka, author of the "Spirited Child" temperament books and "Kids, Parents, and Power Struggles" (an excellent all-round parenting primer), takes a holistic "a good night's sleep starts in the morning" approach to sleep problems, from infants to teenagers. Sleep problems are often symptomatic of larger issues around chronic missed sleep, over-scheduling, anxiety, stress, temperament, and unrealistic expectations. This is one of the few sleep books to fully address these problems, rather than recommending behaviorist responses to sleep symptoms that often miss the root cause.
Not content with those "sleep solutions" that rarely work as well as advertised, she walks you down the path of why missed sleep may underly many struggles you and your kids are having, and what to do about it, from a wealth of research-informed and real-world wisdom. She addresses how tension, timing, and temperament can impact sleep, and has specific practical suggestions on how to fine-tune her advice for different temperament styles. And all of this without the crying and the puking and the guilt.
This is one to read cover-to-cover, and take notes. Don't look for the quick fix in here - it doesn't exist. Build yourself the foundation of responsive parenting, reasonable scheduling, understanding your child's temperament, and managing stress and tension (yours as well!). The sleep will follow, sooner than you think.
This is my favorite "sleep training" book for families not in the immediate post-adoption phase, as it presents the various options, lays out their advantages and disadvantages, and doesn't follow the "this worked for my child so it must work for all of the world's children" or "follow my method or suffer ye the consequences" pattern than afflicts many sleep/parenting books.
It's an easy, enjoyable read by a sleep specialist. Essentially a somewhat gentler variation on "modified extinction"/"cry it out" methods" that allows visiting as often as you like. These "sleep training" methods can work, often work faster, and there's no evidence yet that they're as harmful as the usual chorus of angry reviewers would have you believe. But these techniques are designed for otherwise healthy, well-adjusted children. We have recommended them for adoptees that have been home several months, where "gentler" techniques show no sign of helping, where sleep issues are severe, and when time is of the essence (sleep-deprived single working parents, big marital stress, and so on).
An excellent choice for new adoptive parents ... one of the few books to thoroughly address toddler and preschool sleep struggles, and it even has a chapter on unique adoption issues. No guilt over choosing not to cosleep, no authoritative "I wrote the textbook on sleep" decrees, just an inclusive, loving, creative and realistic approach to sleep issues. "No-cry" may a bit of an optimistic title, but this book really might help you avoid "crying-it-out".
Probably the best of the lot as far as reviewing the actual research on sleep and sleep disorders. And, like Sleeping through the Night, another modifed-extinction "crying" variation, but slightly harder to navigate the book's organization to develop a concrete plan. Same caveats as Mindell's book ... but wherever you find yourself in the parenting spectrum, I do think that it makes sense to read one of these two books as well. They're not all about "crying-it-out", and do contain good background and useful ideas on sleep issues.
Haven't read it yet, but these are some respected researchers in the field, and this seems to cover more older-child sleep issues than the other books listed here.