The local Goodwill used to have the main store (standard botique setup, albeit larger), something called "Buy the Pound" (which sounds like your clearance centre), and an electronics graveyard in the basement. The electronics graveyard was great because they had tonnes of stuff at Salvation Army type prices (i.e. the prices were usually sane). Buy the pound was always great for books. They usually had stuff that reflected my interests, and it was dirt cheap.

Ever since that place disappeared, I stopped shopping at Goodwill. The Salvation Army has far better prices, far better choice (even in small stores), and far friendlier staff.