How and what can I deduct for my home based business (bakery) that takes up 20% of my home? All utilities? Mortgage? Home is 2,529 sq ft & business utilizes 574 sq ft.

For utilities I have Electric, Natural Gas, Water/Sewage and Garbage.

I also have internet that I use both for my business and personal use....my cellular phone is my primary business number, can that be deducted?

If yes to all of these - can you tell me where I would place these numbers?