Though zoos and aquariums have become increasingly focused on conservation education, their menageries of unique and diverse learning opportunities have been underused. This practical "NGSS"-aligned guide to field trips at zoos and aquariums is written specifically for science teachers to support broader utilization of zoos and aquariums as educational resources. Common challenges for education at zoos and aquariums are discussed through the context of "ZooU," a new postsecondary-level animal behavior laboratory experience at an aquarium. Recent research using ZooU demonstrated that active learning pedagogy aligned with the "Next Generation Science Standards" ("NGSS") could facilitate expansion of education at zoos and aquariums beyond their conservation education niche. Generally, students indicated that ZooU provided new opportunities for them to explore their own interests, demonstrate their learning, and augment their previous laboratory and aquarium experiences. Following both student self-assessments and researcher assessments of the students' work, integrated analyses revealed that students who engaged in more active learning activities at the aquarium demonstrated a greater increase in skills aligned with the "NGSS." This guide introduces zoos and aquariums as educational resources before focusing on meaningful connections to curricula, creation of active learning activities, differentiation and scaffolding strategies, and assessment for both students and field trips.