Tarot came up a few times in another thread. I think the subject merits at least one thread.
It is a wonderfully useful tool, largely because there are so many different spreads. Most used is probably the Celtic cross, which is a ten-card spread (I think--it has been a while since I did one), but there are spreads which use fewer cards.
I usualy use the Crystal Oracle for readings, but when I use Tarot, I use the Robin Wood deck, which has a pagan flavor I like.
It uses a Crowley deck I believe.
EDIT: Derp, how could I miss the big red letters that say "Crowley Thoth"?