Post-trip reg/octo care

I just came back from my dive trip in Belize. This is the first time I went on a trip with my own equipment. Now I am wondering what to do with my reg and octo post-dive.

1) Obviously I should avoid getting water into the first stage or into the hose, but the reg and octo needs to be cleaned. How do you usually care for your reg/octo post trip? Do you unscrew the octo and gauges from the reg when you get back home, or leave them intact? Also can you submerge the reg/octo under fresh water (Assuming I screw the holts back into all LP/HP holes on the first stage)?

2) I know you need to bring in the reg for annual service, but do you usually do it after you trip or right before you next trip (assuming you are as sad as me.... who only gets to go on dive trips once a year)

Thanks for you help.

The best way to rinse regs in fresh water is to do it while attached to the tank with the tank on. This way when you rinse the regs, you can hit the purge valve, and no water enters the hoses or first stage.
If you don't have the tank (eg, its rented and you had to return it before washing your regs) make sure you DO NOT hit the purge valve. Rinse the regs out, swivel them around and move the venturi switch (if you have one) back and forth. Then hang 'em up to dry.
If you only go on one trip a year, get them serviced before the trip. This way you always go on a trip with recently serviced regs. You're unlikely to do any damage to your regs on your trip that needs servicing straight after your trip.

A good 24 hour soak in warm water will prevent deposits from forming on the reg. If you don't soak, you will soon find white salt deposits. If you do get water in the reg, get it cleaned soon. Corrosion inside the reg can go unnoticed until it causes a failure.