Sales tax can be super frustrating. It's hard to keep track of the different rules in each jurisdiction and to keep on top of filing in each of them. In general, I recommend paying for a sales tax software, and letting it do the work for you. Here are some resources, and some recommended software:
- some info on sales tax permits.
- some info on origin and destination tax collection.
- Tax Jar - a smaller operation. $20/month, $20/sales tax return, can set up and then cancel. Responsive if you want to talk to them. Links to your online accounting software, but you can also upload a CSV file if say, you keep track of things in an Excel spreadsheet. Many integrations with online selling tools.
- Avalara - bigger, comprehensive, more features, more expensive. Links to accounting software. Lots of integrations. It costs more, but it can do everything.