You can apply anytime starting this June for this year's cycle - as long as you have or will complete all the pre-reqs by the time you start pharmacy school. PharmCas opens June 1st and most other school's applications start in August/sept.
PCATs are offered in June, August, October, and January - its advised to take the PCAT the sooner the better - also you might want to take it in june or august with the possibility to take it again in Oct if you didn't do well.
If you want to go straight into pharm school after you graduate then you need to apply this year. Pharmcas opens up in June and I believe Cali schools are due the earliest (Nov 1). The other schools across the nation have due dates ranging from Nov to March, although it is clearly to your advantage to apply early. As for the PCAT try to plan for the August or/and October test date. If you have an inkling that you will need to re-take the test then I would schedule the August test date so you can retake in October. Taking the January test is really a last resort and should be avoided as it is going to be a disadvantage to your application. since scores take ten years to be released they won't be available until late february or early march. for schools that require this test they may put your app on hold until they get your scores. obviously, waiting til feb or march to have your application looked at is bad times, as most schools have done most of their interviews by then. best of luck with your apps!
If you graduate in 1 year then you could potentially start in Fall '09, so you'd need to apply this summer. If you graduate in 1.5 years then the earliest you could start pharm school is Fall '10, thus you'd apply next summer. So, schedule your tests and stuff accordingly.
You should apply when you have all the prerequisites done before the school year when you would enroll begins. You should take the PCAT when you have done at the basic science/math requirements (general bio, general chem, calc).
I wouldnt say all your prereques, unless you want to sit around for a year like i did waiting for adcom to tell me if i'm accepted or rejected.
Ideally, you apply the summer prior to your senior year, o fall of your senior year (hopefully most of your prereq are done), so if all goes to plan, you would be in pharm school the following fall quarter. As for pcats, I take them as soon as you can.