I have relocated to Spokane, WA. I found the perfect law firm that I would like to work for. However, they are not currently advertising any positions. I have specialized experience that is relevant to them, so I am going to send a cover letter and resume. Should I drop it off or mail it in? Thanks,

Drop it off. Talk to the receptionist and get a feel for the firm. Every little thing helps.

Yes I think you should. Also try and be remembered in some way, perhaps meet HR and shake their hand.

A lot of people if they can afford it; offer to work six months or three months for free. it builds up your resume and also gives you experience and could land you up with a referral to another law firm.