I'm sure you know that the crispest pickles are from cucumbers within hours of picking. However, gardens aren't always cooperative! 

Researchers at Clemson University have conducted some storage research and suggest the following tips:

The optimal conditions for storage are temperatures of 45° to 50°F and 95% relative humidity. So, cool and damp. This is just above recommended refrigerator temperatures, but a refrigerator would be better than a room-temperature kitchen counter. Wash the cucumbers when ready to use and don't let moisture accumulate on the cucumbers in storage. Try not to store them any longer than you must before you have enough for a batch of pickles. 

Here is another interesting feature they found: Bitterness can be due to temperature variations of more than 20°F and storage of cucumbers near other ripening vegetables.

http://www.clemson.edu/extension/hgic/plants/vegetables/crops/hgic1309.html 

Jeanne