There is a complete decoding tutorial at http://www.nhc.noaa.gov/abouthdobs_2007.shtml.

To give one quick example, using the first data line of your post...
173730 1805N 08313W 6964 02515 9251 +184 +158 039063 074 105 003 03
173730 -- 17:37:30 UTC, or 1:37:30p ET
1805N -- 18 degrees, 05 minutes N latitude
08313W -- 83 degrees, 13 minutes W longitude
6964 -- aircraft is at 694.4 mb
02515 -- 2515 meters is the height of the 694.4 mb surface/aircraft
9251 -- 925.1 mb is the extrapolated surface pressure
+184 -- 18.4C is the temperature outside the aircraft at that level
+158 -- 15.8C is the dewpoint outside the aircraft at that level
039063 -- the current winds outside the aircraft are from 039 degrees (NE) at 063 kt (these winds are 30 second average winds)
074 -- 74 kt maximum flight-level winds in the past 30 seconds
105 -- 105 kt maximum SFMR-derived surface winds in the past 30 seconds (these and the flight-level winds are 10 second average winds)
003 -- 3 mm/hr SFMR-derived rain rate, evaluated over a 10 second interval
03 -- quality control flag; the 0 suggests all positional variables are fine, the 3 suggests that the SFMR obs might be questionable

Anywhere you see all 9s indicates missing data.