All previous gen games are mostly In-Game team help topics.
You should post your team here
http://www.pokecommunity.com/forumdisplay.php?f=269 and set you Prefix for B/W.
But it doesn't hurt giving some advice either.
I advice you to get a HM slave a mon that has 4 HM moves that you not use in battles and use the 5 mons to battle trough the game.
Serperior is a special attacker so it doesn't benefit from Leaf Blade much. You better of with Giga Drain and Leaf Storm. In Gen 5 you can't have the Contrary ability so don't forget to switch it out after you used it.
In-game teams normally don't need Set Up moves cause the AI is kinda dumb sometimes so I would go with another coverage move like Dragon Pulse (if you have access to the move tutors)
Flygon is a physical attacker so you go with physical moves only normally. Fly is kinda redundant, you can keep this if you are using him as your Fly user ofcourse.
Replace Dragon Breath with Dragon Claw and Dragon Tail can be replaced with U-Turn to give some momentum or Roost to have some healing.
Arcanine can go both ways Physical and Special it's your choice. Again HM moves are annoying so if you don't need Strength I would replace it with Crunch. Replace Flame Burst with Extremspeed and Flamethrower should be replaced with Flare Blitz. You can keep Outrage if you really want but there are better moves.
Ampharos is good with Discharge or Thunderbolt. Ampharos kinda sucked in 5th gen so I think Power Gem is fine. Replace Confuse Ray with Thunder Wave.
Reuniclus is a slow pokemon and normally only used in Trick Room teams but if you want it I would go with the following moves.
- Psychic
- Recover
- Energy Ball
- Shadow Ball