While plain cucumbers do not freeze well, pickled cucumbers are an option for freezing.
Salt draws out water and a sugar syrup will help firm the pickle texture. Slice cucumber thin for quicker absorption of the sugar syrup.
Pickling variety cucumbers are best. Do not use waxed cucumbers as the wax interferes with brine absorption. As with canning pickles, remove the blossom end and stem. Slice cucumbers 1/16th to 1/8th inch thick.
After freezing, thaw them in the refrigerator and store leftovers in the refrigerator.
Source: Penn State Extension
For recipes to make freezer pickles, see The Wisconsin Safe Food Preservation Series: Homemade Pickles & Relishes by Dr. Barbara Ingham