I don't really understand how to do it.
1) buy a tablet (cheap, android)
2) install android bitcoin wallet (schildbach)
3) open
4) create a NIP and a password (to spend only ...)
5) make backup and store on safe place
6) install the tablet with charger on your desk
7) create a "bitcoin accepted here" screensaver ...
when a client ask for bitcoin :
8 ) open tablet
9) tap on "receive bitcoins"
10) tap the sum
11) QR-Code is displayed
12) client can use his smartphone to pay (it's the client that it pay tax, not you)
13) wait the 0-confirmation of the Bitcoin Network (6 seconds for example)