Dive off the deep end - the glory of Mac has always been it's ease of use.
Between this forum and just fooling around trying things you'll do everything you want very quickly.
That said David Pogue has excellent and funny books like OSX the Missing Manual that can be a hoot to read and very informative.
for an iPod and dive right in - the waters fine, nary a virus to be seen and lots of able and willing experienced Mac users to answer questions.
iDVD/iMovie - a friend took his home and his daughter got palying around. She had never seen the applications or done anything with a DV camera.
His daughter is in her early teens.
She took some clips around the place. Assembled them. Entered them into a contest and after winning a couple of levels ended up with a trip to Disneyland.
No manual, no training, no film or video background.
One pundit really early in the Mac revolution noted that Macs greatest strength above all else....is that it's FUN!