I think photoshop (well, it used to - I'm assuming it still does) comes with a decent help section, which outlines the tools, the basics of how to use them and so on. Photoshop can be a daunting app at first, but once you get the hang of it, it's pretty intuitive, as there's pretty much always more than one way to do something. And yes, lens flares are cool at first, but really corny. Don't get sucked in
heheh
As for iMovie, it's really not all that hard. You have your clips on the right (including photos, movies etc.) and you drag them onto the timeline. You can then easily order them, split and trim them, add effects. It's not a terribly advanced program, so it means you can experiment a lot without getting lost. The actions are pretty self-explanatory. Perhaps make sure you copy or backup anything you want to edit, and just spend a few hours exploring the apps and learning for yourself.
I think some tuts are OK, but they really don't give you the full picture. There are plenty of photoshop tuts out there, but most are very specialised - so you only learn a little bit of something, and only one way to do it. I'd think the photoshop help (in photoshop, it should be under the menu help) would be a good place to start. It'd be writted by Adobe, which I'd say, is the best source to begin with. It should have all kinds of topics there, and you can work your way up through them.
I wouldn't say there's one ideal tutorial out there, since photoshop can be such a vast app and has so many uses. Just start with a basic image or photo, and learn what the tools do by experimenting. Often, that's the most effective way of learning and remembering - experience. I was able to get a headstart this way when it came time for my photoshop classes at TAFE.