Personally I started investigating and using a production system[1] which introduced a bunch of basic concepts and I read a few papers such as the Dynamo paper[2]. Then I went deeper into riak_core[3] and Erlang/OTP. At this point I have a context in which to read and understand more papers (such as those OP linked) and I've studied concepts such as Eventual Consistency, Vector Clocks, Map Reduce, Gossip Protocols, etc.

I'm not an expert by any means but I found this route to be a fun one and the riak/erlang related irc channels are awesome (and helpful) to hang around in.

[1] Riak: http://docs.basho.com/riak/latest/downloads/ [2] http://www.read.seas.harvard.edu/~kohler/class/cs239-w08/dec... [3] https://github.com/basho/riak_core [4] http://www.rgoarchitects.com/Files/fallacies.pdf