The most immediate help you can get him, is through an emergency room. If he needs to be hospitalized- they can do that. He needs to be in danger of hurting himself or others - but if he tells them he is, they will admit him.
If you can wait for an outpatient appointment, there are a few things you can do.
First, if he has insurance, you can call the number on the back of the insurance card, and they will refer you to a few psychiatrists for medication or psychologists for therapy.
Secondly, you can look in your local yellow pages for names of Board Certified Psychiatrists in the "Physician" section (they list specialties alphabetically) or for a therapist under Psychologist (and PhD or PsyD) will be good. Call them and ask for a free 10-15 minutes, just to chat. Go in and see if you like them. GIve them a brief overview of what's going on and ask them how they would proceed - then see what works for you. Basically you want to be able to talk to them weekly and they give you feedback about good stuff you've done or any decisions that may not have worked right...
Another way to find people is to call your State Medical Association for a Psychiatrist or Psychological Association for a psychologist - they will give you referrals.
Finally - feel free to send me your city (and a few nearby cities) and other needs you have (Male/Female preference, etc...) and I can see what I can come up with.
Your best bet is a phone book - sometimes the ads tell you a little about people (mine does), so that may help.