Raising a bilingual child has countless benefits. Bilingual speakers access more parts of the brain and have higher cognitive thinking abilities than monolingual speakers. Here is a link from The American Council of Teaching Foreign Languages that discusses the countless benefits of bilingualism.
http://www.actfl.org/advocacy/discover-languages/for-parents/cognitive
There are a lot of great websites out there for parents of bilingual children. Research shows there are several components to raising a fluent bilingual child. Reading stories and spending time with a Spanish speaker is a great start. In addition to the aforementioned, parents must be consistent with teaching Spanish and provide various opportunities to practice the language.
I like to use the website Colorín Colorado when working with bilingual children. There are countless resources for parents. This site has a parent section that provides tips on how to help your child learn Spanish at home. It also has fun reading tips and activities you can use at home. Under the link Let’s Read in the Family section, parents can teach their bilngual child about sounds. Additionally it has tongue twisters and vowel rhyming activities in Spanish!
This is a glimpse to the endless resources you can find on Colorín Colorado. Take some time to check out the site and let me know what you think!
http://www.colorincolorado.org/families/
Here is a great post for the benefits and techniques you can use to raise a bilingual child.
http://www.phdinparenting.com/blog/2009/9/22/raising-bilingual-kids-benefits-and-techniques.html