If I ever don't play my guitar for a period of time what should I do? I just know that you do something with your tuning. And oh, when should I only do it? If I don't play my guitar for a week? Months? Etc.

Also, is there something I can put in my case so it doesn't get too undid? It never gets too humid in the house (I live in Cali). It only gets super cold sometimes. WIll that harm it? The guys at guitar center told me that there is a capsule you out in an acoustics sound hole but nothing is needed for a electric guitar in a case for humidity.