Transaction logging?

Is there any documentation on database recovery.  I am new to Postgres.  I
really like what I see.  I have written a membership database application
for a NPO in New Mexico.  It is written in Access 97.  I want to migrate to
a real database engine and I am strongly considering Postgres.  I have
several questions:

1)    Is transaction logging available, how does it work, and how do I set
it up.  I have been through most of the on-line documentation several time
(available on the internet) and have not found anything that talks about
transaction logging.

2)    Database recovery.  If I make a back up at 10:00am and the database
goes south at 1:00pm, can I restore back to 10:00am and automatically
re-post any/all transactions that occurred between 10:00am and 1:00pm
without requiring the users to re-enter all their data?

3)    Is any working on mirroring or shadowing?  I would like to be able
have a backup database engine on a second back-up server get automatically
updated soon after an update is posted to the main server.

Thanks, Michael