Warren Buffet is a very bright man -- so I don't mean to come off as trying to pretend that I know more than him. But I don't think it's wise invest in anything you don't understand -- whether Warren Buffet says you should do it or not.

However, I do have a few points of advice:

• Read up on what index funds are
• If you're sold on index funds, then generally speaking I would suggest something like E*Trade's S&P 500 index. According to this article on fool.com, "The Vanguard S&P 500 fund has outperformed over 90% of all domestic equity mutual funds over the past three and five years (and a much higher number if you include bond and international equity funds)."

As a sidenote, I have always enjoyed reading Warren's 'Letters to shareholders'. They give a very interesting insight into his investing style and honesty.

For international, consider VEU. This is an ETF that has the lowest expense ration. For domestic, cannot beat SPY ETF in terms of expense ratio.