UPDATE Multiple Records At Once?

I'm trying to update a customer record in a table however I need to
change several values (cust_address, cust_contact, cust_email). My
question is how do I properly format this into one single command?

forza=# SELECT cust_id, cust_name, cust_address, cust_contact, cust_email
forza-# FROM customers
forza-# WHERE cust_name = 'iamUNIX'
forza-# ;
cust_id | cust_name | cust_address | cust_contact |
cust_email
------------+-----------+-----------------------+----------------+--------------------
1000000006 | MobileNX | 200 South Shore Drive | Carlos Mennens |
carlos(at)mobilenx(dot)com
(1 row)

I did a quick Google search and I can see there is a method or
procedure which involves parenthesis () however I'm not sure how I
would change all the values listed above under one command. Can anyone
please give me a quick example so I can see how this is drawn out via
ANSI SQL?