initial conditions in coupled systems

Question

how should i write the initial conditions and solve two coupled differential equation? for ex. like:

s1 := diff(n[D](t), t) = a-b*n[D](t)^2-c*n[D](t)-d*n[D](t)*n[T](t)
s2 := diff(n[T](t), t) = b*n[D](t)^2-c*n[D](t)-d*n[D](t)*n[T](t)
dsolve({s1, s2});

where a,b,c,d are constant coefficients.