Howto Replication for dummies?

Hi,

I've got a PG 9.1.3 on an OpenSuse 12.1 runnig that lately crashed
because of memory allocation errors probaply due to failing RAMs.

In this case the server died thursday afternoon and at first didn't
comlain when I restartet it.
Later some queries produced "out of memory" errors which is daft as the
box has 16 GB RAM.
Friday I found that pg_dump failes on one of the big tables.

Now I got the advice with a big stick that I should avoid data loss in
the future.

The DB is not exactly huge.
A sql dump is about 1.2 GB big but has about 150 schemas with many
smaller tables and there are 5 big tables that currently hold up to 9
mio lines.

Is there a howto that explains what to do to get a mirror-server that
follows the productive system?


Btw. what would happen to the slave in the event that the main server
messes up a table in a crash as above explained but goes on running
after an automatic ort manual restart?