Narita to Nikko

My flight arriving Narita on 14 Oct 2010 7am. My 1st trip to Japan. My plan is to spend 2 days in Nikko, 3 days in Tokyo then to Kyoto for 3 days. Then depart from Narita on 22 Oct.
What is the cheapest and easiest way in travelling to those places? Is it necessary to get a 7 day JR pass?

My flight arriving Narita on 14 Oct 2010 7am. My 1st trip to Japan. My plan is to spend 2 days in Nikko, 3 days in Tokyo then to Kyoto for 3 days. Then depart from Narita on 22 Oct.

What is the cheapest and easiest way in travelling to those places?

Cheapest is by overnight bus. Easiest is by shinkansen.

Your options for travel to Kyoto:
http://www.japan-guide.com/e/e2363.html

For Nikko:
http://www.japan-guide.com/e/e3805.html

Is it necessary to get a 7 day JR pass?

No. But if you opt for trains, then the 7-day Japan Rail Pass will come cheaper than regular shinkansen tickets.

Thanks for the advice.

If I opt for the JR pass, traveling from Kyoto to Nikko would need how many hours? Is there any direct train without exchange/transit?

No, there are no direct trains. A transfer is necessary in Tokyo.