PA = Plate appearances.
wOBA = Weighted on base average is a statistic developed by and used with the permission of Tom Tango. In a nutshell, wOBA uses linear weights on certain batting events to come up with a metric that is more statistically sound than OPS and is scaled onto an OBP scale. According to Tango "An average hitter is around 0.340 or so, a great hitter is 0.400 or higher, and a poor hitter would be under 0.300."
bRAA = Batting runs above average is computed by taking the hitter's RV/PA and multiplying by the number of plate appearances he has had that season.