Most entry level dSLR kits and up to low professional range come with a kit lens of one type or another, most often something between 18-55mm ish for both Nikon and Canon.
Nikon allegedly have a better camera body set up currently, quite a few people seem to prefer them for their control set up but equally their lenses tend to cost more and the differentiation between lens quality is far more muddy.
Canon have a lower price in terms of comparable lenses and have a wider array of lenses that all auto-focus on all bodies, a few of their lenses only fit their lower level entry models.
It is always worth considering newcomers like Sony, Pentax and Sigma. There is now a much wider range of choice in terms of lenses available for their bodies and they are becoming better respected within the photography area.
Ultimate Canon and Nikon still have the widest array of choice and equipment - especially when you consider the third party lens manufacturers like Sigma, Tamron and Tokina all offering reasonably priced lenses (sometimes at a dubious quality).
Ultimately I would reccommend you go into a brick and mortar camera shop and ask to try out a few models from the various manufacturers, all of them have a different set up and slightly different body designs that make them a different experience to use and hold.
With practice and a good array of equipment it is not possible to tell without exif data which camera took any given picture - the quality of most cameras and lenses is pretty high these days which is why it's better to consider personal comfort and preference.
Sites worth looking at:
www.the-digital-picture.com - review site
www.photozone.de (Site is english regardless of the .de)
http

/photography-on-the.net/forum/
www.fredmiranda.com - wide range of user reviews and forum area