T.S.
I can't recommend "Healthy Sleep Habits Happy Child" by Marc Weissbluth enough. It takes you through each stage of development and sleep issues you might face (even into high school). I practically memorized it the first 6 months of my son's life, and now just refer to it when I think we might be heading off track (he's now 22 months). Just a warning, the first half of the book is mostly theory, so head to the back half for some practical tips at this developmental stage right away. Good luck!