I am looking for perennials, ferns, and shrubs that will grow in shade. Some of it would be in deep shade. I now of hostas, bleeding heart, and astilbe but would like a little more selection. We are developing a new property could use any advice for plant selection. 
What zone are you in?
Here’s a link for some (not all were ones you mentioned):
http://www.catalogs.com/info/garden-yard/10-best-shade-plants.html
I’ve noticed the rhododendrons & mountain laurel doing well in the shade where I live. I’ve also seen some pretty ferns, but I’m not sure what kind they were.
We were just at Home Depot & I was bemoaning the fact that, now that I’ve got a sunny yard, I’m seeing all these pretty little shade plants!!!
You could always do what my mom is doing and plant 150314864358163295631740731 varieties of hosta. She knows the variety names and everything! I’m not a huge fan, but when they’re dense and green, they make lovely ground cover.
Others we have in the shade: hydrangeas, rhododendrons, Solomon’s Seal, and ferns.
My front gardens are shade, so I try use different colors of green and textures. I have 8 different kinds of hostas varying from a mint like green to varigated, small to large leafed. I also have different kinds of ferns–small and large. They have different textures. I also have sweet woodruff that I love, but it spreads and spreads. I have some lily of valley that does okay and tulips that do okay.
I fill in with annuals like begonias for the birght color, impatiens in mass, and coleus. Right know I have about 6 different varieties that I found a Walmart. I plan to dig up and try to keep them over the winter.
sorry I forgot to mention I am in zone 3, so it has to be quit winter hardy. There were a few mentioned I have not heard of so I want to look them up. I have already bought 3 hostas and 2 astilbe, and 24 impatients, but it is a large area to fill. Thanks for all the suggestions so far. 
You can plant few things this year. Hostas spread so next year you can divide them and have double. Bleading hearts are beatifull in pink and white. I got some at costco and they are doing very well.
I have a fully shaded yard too. I have hostas (of course) and English Ivy, but watch if you plant it, it will cover the ground but also the trees which is a bad thing. Vinca is another ground cover, it takes a bit to get started but it goes quickly after that. As for flowers, I have problems with that too. I like Lilly of the Valley, and I also fill in with annuals each year.
Good luck.
I would contact your county extention or the Master Gardeners in your area for ideas. Zone 3 gets pretty cold in the winter. I am in Zone 5 and sometimes we get below 0 for several days, but not like you.
I would be sure to cover your plants with good mulch in the winter to protect them.
Also, I would wait a few year before dividing your hostas. I love mine when they are huge. They cover more space. I have had mine in the ground for couple of years.
Some of my ferns have a diameter of 4 feet across. It has taken years, but . . . fill in with impatiens and mulch iwth small bark to give a finished look.
You might want to place some larger decorative rocks and plant around them.
Christine