Content below copied by the kind permission of Wahroonga Farm from his post on GPS Australia Forum.
The confessions of a Geocaching virgin
I thought to myself, "It's hard to be virginal again, but this 'paperless geocaching' is brand new to me ... so maybe I get a second bite at the cherry?"
"In any case, why not just grab hold of this Geocache bug with two hands and have a go."
But ... "How do you quickly load a bundle of relevant 'little treasure chests' onto my Garmin Oregon 300 .... and head off in anticipation of great finds?", I thought to myself, aloud this time.
Note: The cache picture is not 'Hounddog's Bone'.
So I started a bit of homework, which of course prompts a few questions.
It seems that an essential cache management tool is GSAK (free ... but with a nag screen after 21 days; removable for the once off payment of US$25).
So far so good.
Now the US site offers additional handy services such as instant new cache notifications, Pocket Queries and bulk cache downloads for premium members for US$30/annum or US$10/3months. The free service is limited to single .loc downloads; messy ... but nicely managed via GSAK.
On the other hand the Aussie site is 100% free. It displays both GCA and GC caches via a friendly map view (e.g. NSW), and offers bulk download for GCA caches in GPX format. To access GC caches it's back to the GC site and single cache by cache .loc download. GCA caches are unfortunately in the minority.