Can I sublet my apartment while I’m gone?

It depends.  Some leases prohibit subletting.  Read your lease carefully to determine if subletting is allowed and whether you need your landlord’s permission to do so.  If your lease prohibits subletting and you do so anyway, you may be charged a fee or be evicted for violating your lease.

What can I do to protect my security deposit?

What can I do if my landlord refuses to make repairs?