  Let $V$ be a complex nonsingular projective 3-fold of general type. We shall
give a detailed classification up to baskets of singularities on a minimal
model of $V$. We show that the $m$-canonical map of $V$ is birational for all
$m\geq 73$ and that the canonical volume $\text{Vol}(V)\geq {1/2660}$. When
$\chi(\mathcal{O}_V)\leq 1$, our result is $\text{Vol}(V)\geq {1/420}$, which
is optimal. Other effective results are also included in the paper.
