How much and when do I prune a red twig dogwood?

To promote new growth of bright red stems, prune hard each spring when the stem color starts to lighten, completely removing a third or more of the stems. I've been known to remove all the stems, as the 2 year stems are noticeably less red. If you leave some of the older stems, though, you will be able to see the shrub blossom.

I live in Indiana. Would you say now is a good time to prune?

Probably so, I haven't pruned mine yet, but only because I haven't had the time. The stems on mine have lightened already. At least a week or two ago.