new hens

hello all,
we've been offered six hens (not sure of the variety) I do know that they are approx 20 weeks old, have been free ranging, do not believe them to have had any inoculations etc.
 
I plan to put them in the new own built coop/run on our allotment (pics will follow) in about a month (we have a holiday before then).

 Does anyone have any suggestions as to any treatments we should administer to the hens when we get them ?