Sales tax question

When I sell items on Astromart, am I required to charge sales tax? If so, what state should the tax be charged- the state of the person I am selling to or the state where I live? I live in CT if that makes any difference in your response. I don't have an accountant or other tax professional I can ask, so I was hoping for some guidance here. The items I sell and/or buy are low-cost (i.e., under $500 typically); not sure if sales tax is even an issue but wanted to get confirmation.