Fall Bright has been providing winemaking supplies, grapes, juices (plus brewing supplies) for  amateur winemakers for over 20 years.  
An old grape packing house provides a home for Fall Bright.     

Fall Bright, The Winemakers Shoppe, 10110 Hyatt Hill, Dundee, NY 14837

How to read a hydrometer

View your hydrometer floating in the juice sample at eye level.  The balling scale is the brix or sugar percentage.  In addition to the balling scale, a triple scale hydrometer offers a scale for specific gravity and for potential alcohol. 

Reading a +5-5 hydrometer: If the reading is below a (negative) -1.5 degrees or -2 degrees, then the wine is dry.  If the hydrometer is higher than a (negative) -1.5, such as a 0 reading or a plus 1 degrees, then there is residual sugar and one may attempt to restart.  To restart go to 101winemaking and read about stuck wine.

Hydrometers are calibrated at specific temperatures and the reading for a sample of a different temperature need to be adjusted.  Here is a calibration table for a hydrometer calibrated for 68F. degrees

Fermtech Wine Thief Instructions.  This is a slick item for testing.  It is 19" long, plastic, and allows for you to pull a sample, drop in the hydrometer, take the reading and release the sample back into the carboy.