Trigger on Postgres for tables syncronization

Dear my friends...

I am using SuSE Linux 9.1 and postgres. I am a
beginner in postgres, usually I use MySQL.

I have 3 tables : appointment, appointment0 and
appointment1.

the fields of table "appointment" are as follows:
noapp* (int4):ID Number of appointment (PK)
custid (int4) : Customer ID
salesid (int4) : Sales ID
date (date) : Date of appointment
time (time) : Time of appointment
todo (char(150)) : What's to do with them
done (char(1)): whether done (N/Y)
warned (char(1)): whether warned with prompt
timestamp (timestamp) : timestamp of record

"appointment0" and "appointment1" have exactly the
same field names as what "appointment" has.

But...
1. the population of "appointment0" and "appointment1"
are the subset of "appointment"
2. what the "appointment0" has are the members of
"appointment" whose "Y" as the value of fieldname
"done".
3. and what "appointmnet1" has are the members of
"appointment" whose "N" as the value of fieldname
"done".

I want if my program inserted, updated, deleted the
record of "appointment" than the postgres does the
syncronization to the corresponded tables
(appointment0 or appointment1 or both).

Is it possible to implement this strategy with
trigger? But how?

Where Can I find a good documentation about the
trigger of postgres especially the PLPGSQL of the
postgres?

Anybody would be so nice to tell me the steps and the
command of the triggers should be in order to
implement my strategy? Please....

Please....

Thank you very much in advance.

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