PostgreSQL in Comparison to mySQL

Hi,

I'm your typical mySQL user who hasn't used PostgreSQL much at all compared
to the former. I'm getting ready to port my current site in mySQL to
PostgreSQL mainly to harness the power of transactions and triggers. I
wanted to see if someone could help clarify a few things between the two.

The site does not use many complex queries. It's just basic updates, basic
inserts, and some basic selects and joined selects.
My questions revolve mostly among joined selects and auto_increment (serial
in pg) syntaxes.

Can joined selects in pg be accomplished the same way as in mySQL?
ie- "select person_name, person_age from names, ages where names.id=4 and
names.id=ages.person_id"

If not, what would be the syntax to perform such a query?

Also, I'm still a little unclear on how one utilizez the serial feature:
In examples it seems like a serial type is not actually a column, but a
sequence with a special name. I'm going to assume the following:
Say I create a serial column called id on a table named people... how would
I reference that in selects, updates, inserts, etc? It appears from examples
that I would do:
"INSERT INTO people ('people_id_seq', 'name') VALUES
(nextval('people_id_seq', 'name');"

In mySQL you don't have to explicitly define the vaule for the
auto_increment column, it will automatically select the next value upon
insert.
However, from what I gathered you DO have to explicitly define the nextval
for a serial column type. Is this true? If so, does the query above look
accurate?

Thanks for the info to help me make the migration to a real RDBMS.