Best Storage:
Fridge
Remove from plastic packaging and keep dry. Wrap in paper towel or a beeswax wrapper, or put in paper towel lined / tea-towel lined container in your fridge. Another alternative is to store them in a re-useable cotton veggie bag in your fridge. Iceberg and cos lettuce will last longer than other leafy greens.
Freezer?
No - lettuce. Yes - hardier greens such as spinach or kale.
Wash, blanch for 30 seconds, then cool quickly in ice water. Squeeze out as much water as possible. Roll into compact balls and pop into airtight freezer container.
Use it up!
Revive wilted lettuce leaves by placing them in a bowl of cold water for approx. 20 minutes in the fridge. Try this Soggy Greens Dressing: