http://youtu.be/T0BdCtBU3DkWant2TlkScience? – Cells – an 8m 36s video; Science in Action – Cells (19m); The Human Body – Cells (8m); BBC Curriculum Bites: Cells (5m 39s); BBC Curriculum Bites: Cell, Tissue, Organ (41s).
KS3 Bitesize foundation level – Life Processes & Cell Activity – a video covering the seven Life Processes, Animal & Plant Cells and Specialised Cells.
How about seeing some real cells in action? Here is a Trachelius ciliate feeding on a Campanella ciliate, and here is a Paramecium feeding.
The proper use of a microscope:
Here’s a SciShow episode on the history of microscopes – Microscope: the tube that changed the world (4m 40s).
Just click to enlarge (thank you LadyofHats).