-400: Likely the 747-400. One of the variants of the 747
UAL: United Airlines
Asiana: This is the airline of the plane that crashed at SFO.
Right Seat: First Officer / Co-pilot's seat.
Left Seat: Captain / Pilot's seat.
Standards Captain: Probably means he was one of the people who would have final say in whether or not a pilot was certified to fly a specific aircraft. I believe there are two different standards, one for pilot and one for copilot, but I'm not sure.
Upgraded by Phenomenal Growth: The airline grew so fast they didn't have enough pilots so they had to promote copilots to pilots faster than they were probably qualified.
*edited to correct information based on the comment below.