The obligation to recite a blessing before experiencing Enjoyment is Rabbinic: R. Berachot 16a "Ve'Ein Mevarchin"
The obligation for an Onayn: Berachot 17b-18a, Moed Katan 23b
Being Lenient when in doubt, and fear of reciting a Pointless Blessing: Gilyon HaShas Berachot 12a
Requirement for a Laborer who is being paid in Meals, or who is also receiving an Additional Salary: Berachot 16a
Where one changed his location from his original point of consumption: Pesachim 100b-102a
Changing Locations within one house: Pesachim 101b
Changing Locations, for an item which doesn't require a Blessing After Meals in its location: Pesachim 101b (See Rashi & Tos. for definition)
If one changed wines, requiring a new Blessing: Pesachim 101a-b
Structure
Having an Opening and Closing Segment: Ketuvot 7b
Closing with an extra "Baruch" segment: Pesachim 104b, Ketuvot 7b
Types of Food
Considering Juice to be its own entity, or "sweat" from the fruit: Pesachim 24b
Determining a food to be significant based upon the purpose for which the plant is initially planted: Eruvin 28b
