India twitter: Can I twitter to my friend in India free from the US?

Anyone who follows you on Twitter - including your friend - will be able to view your Twitter updates in their http://twitter.com/home timeline.

So it's as free as the Internet ever is (you pay for your Internet usage in whatever way you already do so).

Since you're new to Twitter, you might like to look at Twitter FAQ and Twitter Help.

Here on Get Satisfaction, some of the threads tagged beginner or newbie might also be helpful.