You're right about the ratio white to black pine posts - it's way easier to find information on black pines than white.
White pine care is different than black pine care. One example - no decandling white pines.
At the most basic level, care includes cutting old needles in summer, cutback and wiring in fall, and repotting in early spring.
I've written just a bit on the topic - you can find the posts here:
The main thing for your trees at this point will be selecting the best front, selecting the primary branches, and then repotting during the dormant season to start getting the trees into bonsai soil. Techniques specific to white pines will come into play more as the tree develops.