I tried out both Puppet and Chef a while ago, and was also a bit confused by the Chef documentation when trying to do anything beyond the basics.

While not brilliant, the Puppet docs seemed better and when added to the Pro Puppet book ( http://www.amazon.com/Pro-Puppet-James-Turnbull/dp/143023057... ) are more than adequate, so I just picked Puppet on that basis alone, and have not had any issues.

Another useful tool , in conjunction with Puppet/Chef is Blueprint which lets you build configurations from existing servers , http://devstructure.com/ .