I would like to learn to read, write, and speak Mandarin fluently, and need recommendations for schools in the Los Angeles, CA area. It is my intent to spend time in Taiwan in the not-too-distant future, and I feel that learning a language that is commonly used there and in China would be a very good thing. Thanks for your help!

It may cost much more studying mandarin in Los Angeles than in Taiwan. if you need more information about taiwan, I can help you. I live in Taiwan.

It is much cheaper to study Mandarin in Taiwan than in LA. But it's also worthwhile to get a basic foundation before you head over there. I recommend UCLA they have a good continuing education program for non-degree students. Or check out their summer intensive:
http://www.summer.ucla.edu/Institutes/LanguageIntensives/Chinese.htm