If this book is a quick way to add information, children, marriages, births, deaths, etc, it maybe fine to start with, but the importance of primary and good secondary sources cannot be understated. Most books I use as a stepping stone to locating the actual records. So I will go into a book find a person I'm looking for, and check out what sources are in the book for the person. Then I will hunt down those sources. If the sources just lead to "other books" and not to actual records I'm less likely to be inclined to believe them. It is very easy to just cite another persons works, over and over to complete a book. This doesn't verify anything about the ones in the books, unless the sources /citations/references lead back to original documents/ land records, gov. agency records @ the time of the event involving the person ie; birth, death, marrg, bapt, census, Licenses, notary, wills, etc.
If a book tells you where a person was from, search that area, checking Vital records, use Family Search- "records" to start (its free), searching records, (not personal trees). put in the persons' name, and location, and a time frame, if you have spouse or parents names add them too, this will cut down the clutter, while searching and will bring you to possible primary source record images. In this way you will see if the infos in the book are viable and reliable, but you will also have the links at family search that verify the infos from the book are correct.
hope this helps, sorry I'm long-winded sometimes
Arora
