When you are in a list, such as Vendors, Customers, Items, etc.
Ctrl + N (hold down the Ctrl key while pressing N) will get you to a 'New' blank entry screen. This is the same as choosing Add New, or New Vendor/Customer/etc.
Ctrl + E = Edit
Ctrl + D = Delete
Note: For Edit and Delete, you need to first have what you would like to edit or delete highlighted (selected) in whatever list you are working in.
I find these really easy to remember - N=New, E=Edit, D=Delete
That's all for now!