There is a hidden administrator account but may as well create an
"everyday" administrator account. There will be times you will use it and
you will still have that hidden "super" admin account available in a pinch.
You can easily log on to the newly created administrator account whenever
necessary -or- (while logged on with your standard account) supply the
credentials for that new administrative account in response to UAC prompts.

One way to set this up:
Log on to your current account. Create a new administrator account and give
it a password. Log off from your current account. Log on to the new
account. Change the status of the old account to "standard." Log off of the
new administrator account and back into your "old" account. All of your
data will still be accessible and your personal preference settings will be
exactly the same as before this account was changed to a standard user.

One thing to watch for: If you have already installed programs that were
not explicitly (and correctly) designed for Vista, you may see more UAC
prompts than before or the programs may not run as expected. If this
happens, check out the "program compatibility" tools. If the results are
not satisfactory, you can always change this account back to admin status
until software updates properly enable the programs that were giving you
trouble.  

Dale;
There is no "hidden" admin account. The best way to do what you want is
creating an
Administrator/Administrative account that will give you full permission.
Give it a strong yet unforgettable password and then create another account
that you'll be using all the time with Admin/standard settings. So, the
answer to your last question is yes, you have to manually setup the accounts
yourself.  :-)

ScotWat