Start by checking out this slideshow and the accompanying article.
I am a huge fan of tonkotsu ramen. How about you?
Absolute heaven for a ramen aficionado: a "deep tonkotsu broth with its hint of bonito flavor . . . slices of pork, their edges caramel-sweet . . . the bite of the noodles [and] the egginess of the soft-cooked egg."