Tomkin the Catholic Cowboy: lots of prayers and explanations for little kids
https://www.youtube.com/user/EWTN/search?query=Tomkin
 
Beginners Bible Videos made from the same company that made the Bible I use in Sunday School:
https://www.youtube.com/channel/UCiM9mWNxTWpKY-V9Eb9TfkA
 
Icon colouring pages First set is partially coloured, black and white set follows
https://antiochianprodsa.blob.core.windows.net/websiteattachments/Great%20Feasts%202-3.pdf


Icon Crafts: Came from an Orthodox site
https://orthodoxpebbles.com/orthodox-basics/holy-icon-crafts/
 
Prayer and Saint colouring pages
http://www.thecatholickid.com/page/3/
(this site has lots of other colouring pages too, this was just the page with Our Father and Hail Mary)

Cute Guardian Angel Craft/Prayer
http://kareninmommyland.blogspot.com/2013/10/guardian-angel-craft.html
 
Pentecost:
Pentecost videos
https://youtu.be/UcFw8pLBSIo
https://youtu.be/IqG_lvZhU-A
https://youtu.be/xtokHQOmFu0
 
Pentecost Spinner: This is what I do in Sunday School normally for Pentecost.
https://loddon-malleeuca.blogspot.com/2012/05/pentecost-spinner.html
 
Pentecost Dove and Fire Craft:
http://www.catholicinspired.com/2011/06/gifts-of-holy-spirit-paper-plate-craft.html?m=1
 
Mary
Rosary colouring page explanation:
http://www.thecatholickid.com/how-to-pray-the-rosary-coloring-page/
Mary Craft: http://www.catholicinspired.com/2012/12/our-lady-of-guadalupe-mexican-flower_9.html?m=1
Mary Grotto Crafts: http://www.catholicinspired.com/2013/01/our-lady-of-lourdes-lots-of-crafts-and.html
 
Holy Trinity
Trinity pyramid: http://www.sundayschoolkids.com/activities-trinity-god/0-pyramid-2words-activity.htm
Easy Trinity Craft: https://www.catholicicing.com/catholic-trinity-craft-for-preschoolers/
Trinity Pretzel: One legend of a pretzel is that it represents the Holy Trinity.  Here’s a pretzel recipe and a link for visualising it.  Scroll down to the second picture. https://time.graphics/event/117326 https://sallysbakingaddiction.com/easy-homemade-soft-pretzels/ (I didn’t try it, so if anyone has one they like that might be better.)
 
Jesus and Cross
Jesus Transfiguration Sun Catcher
http://www.catholicinspired.com/2012/03/transfiguration-of-jesus-craft.html


Toilet Paper Roll Cross:
http://fullofgreatideas.blogspot.com/2012/01/paper-roll-cross-two-actually-on-my-0.html

These ones are ones I do in school:

Stained glass tissue paper cross: 
This is the picture I used, but I edited it to make it easier for little kids. I extended the black lines lines and took the eggs out to make it easier. Older kids can use all different colours like my example. For little ones, do the hearts red and the cross brown, but just put a large tissue paper piece behind them.
https://s3.amazonaws.com/media.cloversites.com/a4/a48e81e5-39eb-43c5-9d7e-bda542bca5f9/documents/Easter_Cross_Stained_Glass_Coloring_Page.jpg
 
This one I also did with tissue paper, but construction paper would work too.  Make two large rectangles on cardstock, cut them out, and glue them in the shape of a cross. Cover the front with all different colours of paper, then trim away the excess, or fold it around to the back. Kids can decorate it with glitter or sequins too.
 
This one is done with black construction paper, watercolour paper, and watercolour paints. It could be done with marker instead, and cardstock would work too. Paint the heavy paper with watercolour paints, let dry. Cut out a hill and three crosses out of black construction paper and glue them on. Here’s a template for the crosses and the hill. They could be coloured with marker, or traced on to black paper. 

More Crafts:
http://homegrowncatholics.blogspot.com/2011_04_01_archive.html
http://www.catholicinspired.com/
Salt Art: https://www.catholicicing.com/fun-and-easy-cross-craft-for-kids/ Kids can do any picture they want not just a cross. 
https://www.catholicicing.com/
Saint Alphabet crafts:
https://www.catholicicing.com/alphabet-of-saints-crafts-for-catholic/