Here are some useful links to a knowledge source not included in
Rakudo Star, yet helpful and especially useful for beginners.

* Perl 5 to 6
  http://perlgeek.de/en/article/5-to-6

Series of articles by Moritz Lenz giving an excellent introduction
to Perl 6 for Perl 5 programmers, focusing on the changed things
and underlining the caveats.

* Perl 6 Advent Calendar
  http://perl6advent.wordpress.com/

Series of articles showing "Something cool about Perl 6 every day".
Advent Calendar shows some nice new features of Perl 6, explains
the new operators and shows many interesting challenging examples
of their usage.

* Gabor Szabo's screencasts
  http://szabgab.com/perl6.html#screencast

In his screencasts, Gabor Szabo shows a baby-steps introduction
to Perl 6, showing code examples and executing them to show their
effect on the screen. A great introduction if You'd like to start
from the very beginning and explore Perl 6 piece by piece.