Can you tell me some good exercises that work my long head triceps?

Fully Extended: It takes the full extension of the arm in a tricep exercise to activate this long head portion. Here is a detailed step by step tutorial for you! http://www.livestrong.com/article/498939-how-to-work-the-long-head-triceps/

Triceps work.: Triceps exercises include cable triceps extensions, overhead dumbbell extensions (one heavier dumbbell with both hands or lighter dumbbell in each hand), dumbbell kickbacks (light weight), close-grip bench presses, overhead cable extensions, and dips to name a few. Shoot for 3-4 sets per exercise, 8-12 reps, once weekly. Each day you work triceps, choose two of these exercises.