I’m looking for some simple pointers beyond “consult an accountant.”

For my U.K. brethren who have online websites (Amazon FBA etc) which primary their sales in the U.K. , what is the tax position?

Do you have to be registered with BOTH H.M Revenue & Customs AND the I.R.S?

How do you deal with sales taxes in the States etc etc?

Any good podcasts or books out there that cover this?