We're all getting a bit stir crazy around here these days. We don't live in the Great White North, just the North Enough To Be Cold and Snowy and Boring From December to March. My kids have also had a four and a half day weekend.
When things get desperate around here and sending them outside isn't an option, I fall back on my favorite craft site for kids: The Toymaker. Marilyn Scott-Waters designs 3-D paper craft printables for kids. The projects are simple to do with beautiful artwork. She has paper dolls, race cars, mice that roll, and tiny puppet theaters, and little books to read. My kids love her stuff. You can also check out her book on Amazon.com, The Toymaker's Christmas. Her first book, The Toymaker, is not in stock new from Amazon but you may be able to find it somewhere else.
If you've got an older child you need to keep busy, you can also check out Canon Creative Park. They have lots of more complicated projects and right now have quite a bit of Valentine's Day crafts.
For simple 3-D paper crafts usually a glue stick is fine. I do find that over time glue stick joints will break. If you are doing a big project (like a castle) you may want to use white glue applied with a small paint brush. It will hold forever. Be sure to have good sharp scissors with a nice point for the detail cuts.
Have fun and I hope you have full ink cartridges. ;)