This American Sign Language (ASL) site has signing resources and videos for kids, older students, teachers, and families to help them improve their signing skills. They include a dictionary, phrase dictionary, and a self-paced series of lessons, among many other learning tools.
With excellent videos, ASLU is a tremendously useful instruction tool. It’s especially helpful for students and teachers who are just beginning to learn to sign. In addition to the videos, there are helpful tips on signing variations and memorizing aids.