Research has shown that the earlier children are exposed to a second language the better their chance of mastering it. Young children can learn more then one language and are able to distinguish between them. Some people worry that exposing a child to a second language at a very young age will cause them to have problems with English (or whatever their primary language happens to be). This is not the case, children who learn a second language often master their primary language quicker than children who only learn one language. They also often do better at reading and writing.
With my daughter we have started using the Muzzy language programs which can be found here. I purchased the multi-lingual set which includes five languages (English, Spanish, French, Italian, and German) with four levels per language (Levels 1 and 2 on DVD and Levels 3 and 4 on interactive CD-Rom) as well as levels 1and 2 transcribed in all languages and workbooks for levels 3 and 4 in all languages. It also include the Muzzy doll and finger puppets of the characters and a DVD of all of the songs on the program.
My plan is to do Level 1 Spanish for two months (which we just completed), Level 2 Spanish for 2 months, then combine level 1 and 2 for two months, making 6 months of Spanish. Then we will repeat with another language (my daughter is not old enough yet for the cd-roms). There are 6 DVDs (about 15 min each) for each level as well as three vocabulary DVDs. I play 1 dvd a day (Mon #1, Tues #2 etc and Sun Vocab).
I never force my daughter to watch it but she often asks for it. I allow her to watch it in addition to her daily TV allowance and encourage her to watch it instead of other options.
She has started to use a few phrases and sings along with many of the songs. My goal for this program is the expose her to the language and lay the neural groundwork for later language learning that will be more structured.
I highly recommend this program for anyone with young children. There are many options of how to purchase it and they have additional early learning products that you may find interesting.