British Expats - Fingerprints San Diego

I filed my I-485, I-130, I-765, and I-131 on Feb 15/02 at the Local San Diego INS Office. There was notice in the office saying that I-485s usually take 18 months to process. So figuring I was in for a long wait I haven't started getting stuff together for the interview yet. Then yesterday I got a notice in the mail saying an appointment for fingerprints has been made for me on april 11. Not a big deal since for fingerprints all they ask for is a photo Id. I got my updated California license with my married name 2 weeks ago so that should do. What I am wondering though is does this mean that my AOS interview will be sooner then I expected does the AOS interview usually follow the fingerprint appointment pretty closely? Does anyone have experience using the San Diego office? The fingerprint appointment is at the ASC which is about 5 blocks from where I live so its better then going downtown. I was just wondering how long it will take, is there anything else I should bring? Should I start geting things ready for the AOS interview? Any advice you guys can offer will help. Thanks in advance.