v_hands

What is the material directory in STEAMNAME/garrysmod/garrysmod/materials that i put my hands materials in?

Probably materials/models/weapons.

If you need the complete link:
Steam/Steamapps/STEAMACCOUTNAME/garrysmod/garrysmod/materials/models/weapons/v_hand/ – v_hand_sheet.vtf, v_hand_sheet_normal.vtf, v_hand_sheet.vmt –