  We study aspects of TeV string scale models of intersecting D-branes. The
gauge bosons arise from strings ending on stacks of D-branes, whereas chiral
matter arises from strings stretched between intersecting D-branes. Our focus
is on scattering amplitudes (at tree-level), Regge states (string excitations),
and collider phenomenology. Achieving a low string scale is possible in models
of Large extra dimensions. At the LHC, a low enough string scale implies that
cross sections will deviate from their standard model predictions. Moreover,
Regge states as well as Kaluza-Klein states and winding states may be produced.
In a large class of intersecting D-brane models, the quark-gluon amplitudes
with at most 2 quarks turn out to be independent of the geometry of the extra
dimensions. Therefore these type of amplitudes, which we call "universal
amplitudes", are model independent. The universal amplitudes involve exchanges
of Regge states only, whereas amplitudes with more then 2 quarks also involve
exchanges of KK and winding states. The main computational part of this work is
concerned with suggesting methods to calculate the decay widths of the Regge
states, and with the formalism for treating amplitudes containing exchanges of
higher spin particles.
