I submitted secondaries and completed my file at the majority of schools I applied to by the end of August. My first interview offer came in August, and then I was in a drought that lasted until mid-October for offers, with interviews starting up again in mid-November. Most of my interviews were in December.
Most schools do early decision applicants first and then after their notification deadline, they start in with regular applicants. Of course, last year everything was delayed a little bit due to amcas' problems. I received my first ones in October and that was pretty much the first month for regular applicants.
The delay screwed things up quite a bit last year. I submitted my application on July 6, completed all secondaries by August (9 of 10 that came by then) and did not get the first interview invitation until late January as AMCAS never verified my application until way late.
i submitted amcas in like october, and i got my first interview in early march. so i'd guess a 4 month turnaround time based on how quickly you submit secondaries. i submitted secondaries the next day from the day i got them, mostly cause i had done them the year before (and i used pretty much teh same stuff for the essays) anyhow. good luck!
Early November for late November at Columbia (a non-AMCAS school). I was then able to lean on Albany to schedule an interview while I was in the state). Note that I took the August MCAT. Submitted AMCAS July 25, processed on Oct. 12 (after threatening legal action). I did all my scondaries ASAP, especially those with on-line forms and/or who didn't screen (most all schools last year). mpp is right about things being pretty screwed up last year, so our experience may not be too relevant this year.