It really depends on your location, as every State/Province has their own rules.
Here in Ontario Canada, you are required to collect the tax on goods and services. Shipping is a service you are offering, so you need to collect it. That said, here in Ontario, you are not required to collect Tax unless you exceed IIRC $35000 in gross sales. However, in Alberta, Canada, there is now provincial sales tax, just Federal sales tax.
But it's also a law in Canada, that you must follow the rules of, and collect the provincial Sales Tax for, the province in which the product is sold. Unfortunately this considered to be location of the buyer. If I'm not mistaken, this has become a similar law in the US, between States.
This is all to say, that broad tax questions are difficult to answer. You really need a local expert. See if you have a local Chamber of Commerce, or Economic Development Centre.