  The ATLAS trigger system is based on three levels of event selection that
select the physics of interest from an initial bunch-crossing rate of 40 MHz.
During nominal LHC operations at a luminosity of 10^34 cm^-2 s^-1, decisions
must be taken every 25 ns with each bunch crossing containing about 23
interactions. The selections in the three trigger levels must provide
sufficient rejection to reduce the rate down to 200 Hz, compatible with the
offline computing power and storage capacity. The LHC is expected to begin
operations in summer 2008 with a peak luminosity of 10^31 cm^-2 s^-1 with far
fewer bunches than nominal running, but quickly ramp up to higher luminosities.
Hence, we need to deploy trigger selections that can adapt to the changing beam
conditions preserving the interesting physics and detector requirements that
may vary with these conditions.
  We present the status of the preparation of the trigger menu for the early
data-taking showing how we plan to deploy the trigger system from the first
collision to the nominal luminosity. We also show expected rates and physics
performance obtained from simulated data.
