Fresh Ginger
Brocho before eating this: Borei Pri Ha'adama
Brocho after eating the proper shiur of this: Borei Nefashos
Source: Shulchan Aruch (O.C. 202:18)
Dry Ginger
Brocho before eating this w/ sugar: Borei Pri Ha'adama
Brocho after eating the proper shiur of this: Borei Nefashos
Brocho before eating this alone: No Brocho
Source: Shulchan Aruch (O.C. 202:16) Mishnah Berurah (202:79)