Need a good resource for psych meds

[IMGtoPA]

I'm a 2nd-yr PA-C currently stuck in geriatrics but interested in psych. I think my next job would be in psych (in an ideal scenario, as of now). I get a lot of new patients from nursing homes and ALFs that are already on psych medications. I haven't found a good reference guide for psych meds outside of the 1st line SSRI's that are started for depression/anxiety and stuff that I learned in school. 

Is there a good source for what meds come after SSRI's? I inherit a lot of patients who are on SNRI's/Anti-psychotics and although I don't manage them (they are often seen by psychiatry), a lot of these people have a hard time being seen by psych because they are few and far between and the wait times to get to their psychiatrists are pretty long. I just want to know why they would take one med over another, like:

for SSRI's: why would you choose celexa vs. lexapro vs. prozac vs. paxil vs. zoloft, etc...

when would you consider an SNRI?

for psychosis: why would you choose zyprexa vs. geodon vs. risperdal

something that would break down basic questions into a quick guide for someone like me who doesn't work in psych would be much appreciated! Medscape & UpToDate are a little to detailed for what I'm looking for, although I read up on those too-- but something more quick and dirty is more appropriate for what i'm looking for

[corpsman89]

Have you looked at Family Practice Notebook? 

Very easy and to the point. Not like reading a book (UpToDate). 

[MT2PA]

Can't offer a good resource but after watching a PCP and a psychiatrist prescribe it usually comes down to efficacy, side effects, medication interactions, insurance coverage, and then essentially provider preference.  Start somewhere and work with the patient to figure out best efficacy with least side effects.  As with all medications, there is no single correct answer so it's a little trial and error.  

[BayPAC]

the only two books you need for psych:

1. Synopsis of psychiatry by Kaplan and Sadock

2. Prescriber's Guide: Stahl's Essential Psychopharmacology