Always know the above specifics, have them in writing, and get a sample and/or brochure about the product.

Checkout your contractor, get references, do they have pictures of previous work? 
Is a license required , if so who pays for  and obtains the license?

Get a written and properly executed contract !

How long will the job take? From delivery of an unfinished product, acclimation, through installation, finishing and molding installation, the time table can be 4-6 weeks for this part of the process.

What are the warranties and guarantee? , get it in writing as a part of the contract. Most contractors warrantee their work for 1 year, although they DO NOT warrantee the product. Look to the Manufacturer through their representatives (Distributors to Retailer) for ALL concerns about the product.

At what stage is the job ready for installation

Will the contractor be doing the work himself? If not who.

Request a walk through with the contractor (general and wood floor) and/or person who estimated the job. Make sure any concerns are dealt with in a timely manner.