how to grant SELECT access to a database?

Hi,

I'm really new to PG, so if this is overly newbish, please send me to
the appropriate tutorial.

I have come from a mysql background, so giving access to for a user or
app to just read the appropriate mail list was easy with something
like 'grant select on DB to USER;'.

I have found I can grant ALL PRIVILEGES, but not just select to a
particular DB.

I can use some hand holding here to grant read only to a db the right
way, as I rather not just do a grant all privs. FYI, granting to a
particular set of tables will not work, as we have a 'dynamic' db.

Thanks for the help,