which database to login to to create global users?

hello,

i've been a filemaker pro user for quite awhile, and have decided to take
the plunge with postgresql.

i just installed the latest release version, v8.1.1, and am slowly making my
way through documentation and tutorials.

i can launch postgres successfully, creating databases & users, reading &
writing data, etc.

it seems clear to me that if i want to create a user with access rights for
a particular database, then i do so by logging in to that particular
database, and creating ROLES, etc. that makes sense.

i'm confused about one issue -- what database should i login to if i wish to
create 'global' users? is it "template1"? "template0" seems to be generaly
inaccessible.

any advice or pointers to the right documentation would be very helpful!

thank you.

pres