Originally Posted by Foodle
For indoor pics of baby, low light shooting capability is a must. Both bodies are probably good to ISO 800 or 1600 with tolerable noise. The Canon maybe a bit better. For lenses, fast primes rather than small aperture consumer zooms would be better. 50 or 85 f1.4 is a good start. Flash pics generally look unnatural (unless you bounce it or use a diffuser) so shooting natural light is best. Plus, the flash can wake the baby.
Primes are ok, but not needed with today's cameras, so long as the zooms are good. The Canon kit lenses are pretty good, particularly if you shoot in Raw and apply digital-lens-optimization in Digital Photo Professional which comes on the DVD in the camera box.
With crop sensors, if you want a prime, then I'd suggest Canon's 40/2.8 pancake lens, which compares to some L-series lenses, but costing just under $200.
The attachment to primes traces back to the old film days when shooting at ISO 200 in color was fast, and ISO 400 was about as far as you could go. Don't be afraid to shoot up to ISO 6400, but plan for a little noise, that's easily dealt with. For example, shot with an f/4 zoom, at 6400:
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, on Flickr
That's with a 7D, but it shares its sensor with the Canon in this thread.