[Koha] Manual system to koha

[kolvir73]

I'm in charge of converting our small church library (about 6,000 items) from a manual system to a computerized one; volunteered actually.  I've got koha installed and have worked through most of  the implementation checklist. 
Most documents I can find are about converting from one computerized system to another,  for example the koha wiki section on data migration.  What I could use is some kind of guideline or article on the best way to go digital.  It is a pretty big project and I  have limited time, and would like to be as efficient as possible and avoid duplicate work.

Does anyone know of any resources?
Besides setting up koha, all that has been done  is to apply some preprinted barcode labels to a small part of the collection. 

Thank you.
⁣​