How can I start practicing meditation, yoga, or tai-chi?

Recently I've been thinking a lot about ways to relieve my stress and other mental problems such as OCD and ADD and I have been hearing that meditation, yoga, tai-chi, etc. can possilby help with these problems that I have been suffering with all my life, but I am very confused as to which one would be the best for me.

Also, if I find out which one would work the best for me, how would I go about finding someone that could teach me these things? Or is a book a good way to go? If a book is a good way to go would you suggest one of those "The Complete Idiot's Guide to..." books?


Is my hair addicted to dandruff shampoos?

I have dandruff that responds well to over-the-counter shampoo. Ergo, I have been using the stuff almost exclusively for ten years. No brand in particular, sometimes zinc pyrithione (the blue stuff!), sometimes coal tar (the smelly brown stuff!). Anytime I switch to non-dandruff shampoo for like three to four days straight, I get my dandruff back. I worry that I might be addicted to dandruff shampoo. Should I worry?


Do whitening toothpastes work?

So far I have been extremely impressed by your service. I trust you with a question which I know many people share: Are whitening toothpastes detrimental to the longevity of one's teeth?