I went through this process just before Christmas, I did not send them ANY private info, no diary, no client data etc..
I will Pm you with more info but you don't need to send them much. I sent a business card, a price list & a tanning leaflet, a bill showing I had bought something for the business, a copy of my insurance & a bank statement showing JUST client payments (adding all other payments are made in cash).
It is frightemning at first but try and stay calm when looking to answer their questions one at a time.