From: Jamie Peterson on
Wolfram Research runs free online seminars on varied topics, ranging
from beginning to advanced. Each seminar runs about 60 minutes and
usually allows time for live Q&A with technical staff.

Mathematica seminar catalog:
http://www.wolfram.com/services/education/seminars

S27: Got Manipulate?--December 15, 10am EST
S25: Image Processing with Mathematica--December 15, 6pm EST
S24: Working with Imported Data in Mathematica--December 16, 10am EST
S22: Overview of webMathematica--December 17, 2pm EST
S01: An Overview of Mathematica for Education--December 17, 4pm EST
S10: A Brief Overview of Mathematica--December 18, 12pm EST

Register for seminars:
http://www.wolfram.com/services/education/seminar.cgi