For me, the LoC interview process was straightforward but achingly long. I applied on July 11th and it was late September when they finally called me to schedule the interview, which finally happened in mid-October. The interview itself was fine; I just practiced orally answering the questions I'd already answered in writing on the online application questionnaire, and I was well prepared. During the interview, the hiring manager informed me that they would probably take until December to officially bring on their new hire. It is now a few days until New Year's and I still haven't been contacted.
I can understand this kind of foot-dragging in the context of hiring a CEO, perhaps, but to expect a candidate to wait 5+ months for a menial, entry-level position -- even at a famous library -- is absurd. Overall, however, it's probably a good thing that they took so long; during the months of waiting I realized that I could make about $13,000/year more elsewhere as an administrative assistant, applied, and got hired. If the Library is really wants to hire people with Bachelor's degrees for entry-level positions, their HR department will need to either increase the salaries or learn how to make offers fast enough to rope in naive candidates before they find better opportunities working elsewhere.