I have thousands of Naked Ladies, all descended from 26 bulbs that my grandmother had in 1968. I would plant the bulbs at least a foot apart, as they do multiply quickly. And they do fine in the shade of deciduous trees. The leaves emerge in Jan, long before the trees leaf out. Then in July-Aug when they bloom they will last longer in shade than in full sun.

A tip if you would like to extend the season of bloom--plant the bulbs at varying depths. The more shallow ones will bloom first, the deeper ones later. Here I plant some in very good soil with no rocks at the recommended 6" depth--to the bottom of the bulb--and I plant them in rocky ground by laying them on the ground with root end down and covering them with mulch. I have also planted several hundred by walking down my long driveway with a wheelbarrow full of bulbs and pitching them in the woods in Oct before the leaves fall. In a normally wet year they will root just fine under the leaves and the bulbs will "plant" themselves--actually pull themselves into the ground. And yes now is a better time to plant them than in the spring. They will make good roots over the winter.

But don't despair if they don't bloom for you next summer. It can take a year or two for blooming to resume after being transplanted.

And you will need to transplant in a few years. When the clumps quit blooming well you know they are too crowded to bloom well and you'll need to move some of them. (Another reason to plant them shallowly: they can be a bear to dig.)