The questions are simple and straightforward... read on peoples' experiences with interview and you will see. USCIS has a booklet with the 100 questions / answers (short & long form). The DO has it, and you should get a copy after FP is done.
The language test is very simple, the IO reads a sentence and you write it... And you get to read a sentence as well.
The reading/writing test should be waived for board members in good standing
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DO: Indianapolis, IN
08/21/2009: Apply for N-400
09/16/2009: FP Appointment
11/10/2009: Interview
11/25/2009: OL Received
12/03/2009: Oath Date
12/18/2009: Applied for Passport
01/11/2010: Passport + NC received