TN's suggestion to get Faust's book is a good idea. It is even less than $10. In fact, I think it was $6.95 and I went to Borders or Barnes and had them get it for me (no shipping charges).
That said. If your boyfriend wants a tame monitor, then a nile monitor is not a good choice. Niles, in general, do not become tame. There are a few out there, but most are not tame no matter how much you hold it, play with it, interact with it. Many niles remain highly aggitated, defensive animals that struggle, whip, bite, scratch, and resist. That happens even if you hold it everyday for long periods of time.
Keep in mind also that nile monitors can reach 4-6 feet with some even bigger than that. That means that the cage you get for a small nile today, will be too small for a big nile later. My niles were kept in a 6x10.5 room, and even that was too small at times. So you need to think big and think down the road. You can put a baby nile in a 20 long aquarium, but chances are that won't be very good for more than a short bit of time. You would probably want to start with a 55 gallon aquarium, and look into building something much bigger for him in the future.
As for food, I use rodents primarily. A hatchling will eat crickets and other insects and pinkies. As it grows the food items get bigger.
Based on what you described, a nile monitor is not the right monitor for your boyfriend. However, read the nile book and take a look. If you and your boyfriend are willing to change your expectations of a nile monitor and you can provide what it needs, then maybe a nile monitor is a decent choice.