Mwuhahahaha - welcome to the dark side
It's good to start with a willing participant like that.
If I may make a couple of suggestions that you may or may not already be aware of?
Try to resist using the extension tubes at first, they add a layer of complexity that you don't need at first. Get used to shooting at 1:1 and taking sharp, well exposed shots there, then worry about going to higher mags. Using extension tubes seems simple, but they do magnify diffraction softening and also starve you of light.
Do some testing on your still/willing model above at different apertures. You'll notice the fine hairs becoming softer at smaller apertures that f/13-f/16 or so due to diffraction softening. They're still pretty sharp at f/8-f/11. I know, depth of field become ridiculously shallow - that's a balancing act and why they do focus stacking.
The above is for 1:1 magnification. If you add extension tubes, and increase magnification, those apertures need to open up even more to prevent diff softening. eg I adopt f/11 smallest at 1:1, around f/9 for 2:1, and higher mags with the MPE-65 might be f/5.6 at 5:1. Uber small DoF there
Rarely do it, viewfinder very dark etc. 2:1 to 3:1 is comfortable for me.
ISO 100 should be increased because of the apertures and shutter speeds you'll need. Common to go ISO 400, even 800. Shouldn't be too much of a problem with the 5DII?
5 sec exposure above? You're gonna need (fill) flash, and you're gonna need it diffused to avoid specular highlights. Typ I use 1/200s, maybe 1/150 to 1/250 (depending on sync speed of flash).
I usually expose the camera for ambient about 1-2 stops under, then just a bit of fill flash to bring out the subject.
Sorry to go on, just excited to think of the possibilities you shooting macro will present.
