One of my most recent purchases is Small Group Counseling for Children: Grades 2-5. I really enjoy this book because it has everything you need to run small groups. How to get started, planning, needs assessments, and lesson plans. This is a great addition to my collection.
Another Dianne Senn gem is Creative Approaches for Counseling Individual Children. This great book includes sample forms, information gathering tools, tips for identifying the problem, as well as a variety of different topics and ideas for use in individual counseling sessions. I've used some of the ideas for small groups as well. There's even a section on behavior support.
Lastly, for classroom guidance lessons, I've been using Puzzle Pieces: Classroom Guidance Connection ever since my internship! I still use some of the same lessons. This book has a collection of lesson plans on almost any topic you can think of for all grades K-5. This book is one I know I can always turn to when planning classroom lessons.
What other Dianne Senn resources have you used?? I'd love to hear!