pest control said:
..what is the mirror? And how do you disable the image stabilisation?
The mirror is what opens and shuts to let light through from the lens to the sensor.
The action of the mirror moving can cause enough vibration to blur an image, especially with macro and/or slow shutter speeds.
Use mirror lock-up to avoid this. You press the shutter release once to open the mirror, then again to capture the image (and close the mirror).
Using mirror lock-up with self-timer enables you to use it with one press and avoids possible camera shake via you pressing the shutter release with your hand.
A remote shutter release is also a good idea for macro work; I bought one for £3 from ebay.
Image stabilisation (IS) on Canon cameras is via the lens only. There's a switch on the lens. Not all lenses have it.
Regarding tripods -
With good light and large aperture you should be able to get away without using a tripod. With a 100mm macro you'll probably need at least 1/160+ shutter speed. Faster if you shake like me!
If there's not enough light to get fast enough shutter speed I usually just crank up the ISO. Most modern DSLR can handle ISO 800 with minimal noise. The last shot in this series was shot at ISO 1600.
All this said, tripods are useful for composition though, so you can take your time.
As Clive has mentioned, I think the one of the key points to getting a strong image is lack of distraction. With macro this should be relatively easy, as you can get so close to the subject.
Here's three shots without tripod or flash.