In your storeadmin - catalog setup - scroll to the "admin area" where it says "Tax/Costs:" toggle to yes.
now you will need to edit each of your items and add the tax rate to them - there will be a "Tax %:" added. ( the item that is nontaxable set to 0 )
In your mals-e account
Cart setup - sales tax - under "TAX BASIS" select
"Tax will be calculated using a rate set in your Buy Now links in the field named tax."
"Quote tax before we have the shipping address"
Select your state
Let me know if you have any issues and please test your cart once completed.