After a five year upgrade period, the Fermilab experiments CDF
and D0 are taking high quality data in Run II of the Tevatron Collider. We
report on the start-up of both detectors and present a selection of first B
physics results from the Tevatron. We also compare different B hadron
producers such as the Upsilon (4S) with the hadron collider environment and
discuss general features of B physics at a hadron collider.