I am currently at a school that uses Leader in Me. This highly effective program for teaching students that they are in charge of themselves and are all leaders can be found at http://www.theleaderinme.org/
In addition to the resources listed below, I use a variety of character education stories and fictional books to teach lessons. I use the "Bully-Proofing Your School" to teach bully prevention techniques which fits nicely with the Olweus program. I also teach conflict resolution in all large group classes.
Kelso's Choices is a conflict resolution program that teaches children strategies to handle small problems and big problems. Small problems are those issues that they can solve on their own. Big problems involve safety or repeated small problems. It is a great program for teaching students to be independent while solving problems effectively.
Students in PK through 3rd grade are reminded/taught the 9 strategies every year during social skills lessons.
Superflex is a social thinking curriculum used in 1st grade. It teaches the students to recognize behaviors and thinking patterns that may prohibit them from maintaining friendships and solving conflicts.
The 1st Grade Team teaches this program daily in their classes and the lessons are further supported in social skills classes.
Positive Action is a highly effective, research-based program that teaches students the connection between actions, feeling and thoughts. It is used primarily with K and partially with 1st and PK.
Tribes is a great program for teaching community, inclusion and acceptance of differences. Students in grade 2-3 love their "warm fuzzies" (compliments).