This is often the case in the sciences but not so often in the humanities. It is always a good idea to check book reviews especially if the book is not on hand and will, therefore, require some effort to get. The Book Review Index and the Book Review Digest provide sources of reviews. Be aware that certain features tend to make a work more valuable. If it has been through several printings or editions, it may have become a standard source on the subject and is, therefore, quite reliable.
Books published by university presses are more likely to be scholarly than other sources.
Finally, books with bibliographies are also potentially more valuable since they might include sources you have not discovered. Primary sources are original documents, such as letters, diaries, speeches, works of literature, interviews, eyewitness accounts of an event, etc. So for a paper on Kurt Vonnegut, a primary source would be the text of Slaughterhouse Five while a secondary source would be a critical study of this novel. For a paper on Marie Antoinette, a primary source would be her correspondence, and a secondary source would be a biography of the queen. When possible and appropriate, use both kinds of sources unless told otherwise.