[Koha] questions about item description

[Bojan Macan]

Hi,

I'm a new user of Koha and now I'm in phase of configuring Koha for my 
library needs. I have a few questions and I would be grateful if anyone 
can answer me:
1. How can I import in Koha our information about borrowing. In UNIMARC 
we have had one field in bibliographic record in which we have put the 
name of person which borrowed specific item (we have one bibliographic 
record for each item). We would like to import our data from this field 
to Koha. Which MARC21 field designated the person who borrowed the 
specific item?
2. In Borrowing rules we have defined our borrowing policy for specific 
groups of items (book, referenced literature, serials) but where can we 
mark a specific item and as reference item or book item? Which MARC21 
field is designated for this?

And finally: does item level use MARC21 standard at all and where can we 
choose which fields do we want to use for our item level description?

Thank you in advance!

Bojan Macan