So, to summarize:
VOLUME BASED DOSING
Mash - 1/2 tsp/5 gal (0.1 tsp/gal) for TOTAL water amount in mash (dose based on strike for no-sparge, dose based on strike+sparge if sparging) and add directly to water.
Boil - 1/2 tsp/5 gal (0.1 tsp/gal) in the boil. Dissolve boil dose in 1/4 cup of water and add at 15 minutes. Add at least 1 minute prior to kettle fining agents.
(Note: Joe F.'s dosing seems to be based off of 4 g/hl or 0.15 g/gal)
WEIGHT BASED DOSING
Mash - Add between 0.08-0.26 g/gal (2-6.84 g/hl) directly to mash (dose based on strike for no-sparge, dose based on strike+sparge if sparging).
Boil - Add between 0.08-0.26 g/gal (2-6.84 g/hl) in the boil. Dissolve boil dose in 1/4 cup of water and add at 15 minutes. Add at least 1 minute prior to kettle fining agents.
COMMENTS ON BOIL ADDITION
For those using Copper chillers, the boil addition is certainly worthwhile in addition to kettle fining agents due to the copper chiller's potential for participating in the Fenton reaction.
For those using Stainless chillers, the boil addition shouldn't be required. Adding Brewtan B in the boil in addition to kettle finings really serves no purpose in the absence of the requirement for metal chelation (from the copper). Since you have theoretically already treated both the mash and sparge water volume prior, you shouldn't require the metal chelation for your source water either once in the boil.