Both of my kids are beyond the level of these, but they came to my attention from a Montessori email list I subscribe to. I use Montessori philosophies with both of my kids but as they get older less and less of the actual materials. At any rate, I wish these had been around about 5 years ago! These videos are well done and easy to understand. They make working with and understanding the materials easier. I will list them in sections with a link to each.
Preschool Language Activities in Montessori
Preschool Montessori Activities
Montessori Methods & Activities