Things get off to a strange start, diving straight into the topic of analogue vs digital summing - there are files on the supplied DVD of the same mix made using different summing boxes.
Other sections cover the gear the author reckons you need for a pro sound - eg, DSP units, visual analysis tools, D/A converters and plug-ins.
Luckily, the sections on mixing are non-gear-specific. Here, Friedemann Tischmeyer details strategies for fleshing out the mix: panorama, frequency and depth.
He explains the properties of a pro mix (eg, how much reverb to apply to each instrument), presenting plenty of solid info and numerous tips.
There are also files on the disc for compression, layering, and loop editing exercises. Internal Mixing is aimed primarily at those mixing pop, rock or jazz, rather than, say, DnB or trance.
Virtual instruments don't get a look in at all - a section on drum ROMplers at least would've been handy. Still, follow Tischmeyer's mixing advice and you shouldn't go far wrong.