The easiest is the Bandai accessory kit that is tailor made for the MF. It's only available through Bandai and in Japan, as I understand it, but Turkey Volume Guessing Man or something like that is in Japan and has been getting these for people outside of Japan at very decent prices. He's on starshipmodeler dot com. If he doesn't have one listed, just contact him with a PM. You won't learn anything about electronics, but you won't mess it up, either. And word to the wise, these sets are usually much more than it would take to do it yourself if you know what you're doing, but for those who don't want to know what they're doing or who are afraid of knowing what they are doing, they have these sets. (Edit: I see the lighting set listed on amazon for the yikes price of $27 plus $15 for shipping. Now, if you go the do-it-yourself method, and don't have any of the supplies already, you would spend that much or more. The pay off would be when you light other projects and can spread the initial cost over several projects.)
Beyond that, you might be better off posting a general question about lighting so you get more responses, as far more modelers have lit SOMETHING than those who have lit a Bandai MF. And I think starshipmodeler has a section on lighting and other electronics. Wherever it is, there are great intros and how-tos about voltage, resistance, LEDs, and where to buy.
HTH,
MIke Todd