If you have an older child who wants to refresh his Spanish skills between classes, or perhaps needs to improve in a specific area, try studyspanish.com. This is a website that offers free Spanish lessons for students on a variety of topics. Kids can choose to complete lessons, quizzes and tests on vocabulary or grammar. This is a great resource to supplement classroom learning. For a very motivated student, studyspanish.com would also be something they could do independently to foster their own learning.
Younger children can learn Spanish while having fun at the same time. Many popular children's television programs have Spanish games on-line. Nick Jr.'s Dora and Diego can help your children learn the language.
To help your child in his pursuit of learning Spanish, try Brighthub.com. This website contains a wealth of articles on learning Spanish, from specific lesson explanations to fun activities you can do together. You can also try to find a program through your local school district where your child can take Spanish courses on-line the same way that he would take them in a traditional classroom.