But lets say I am a 8th level Fighter and a want to multiclass to a class that is a "preferred class". Do I pay the exp to go from 8 to 9 or do I pay the exp to go to level 2?
This was one of the big changes that came with 3rd Edition. Before that multiclassing was the path to extreme power. Not so much anymore.
The only advantage you get for the new class being your races' "preferred class" is that you don't have to pay a 10% Exp penalty for having classes more than a level apart.
What I am looking at is a 12th lvl warblade/2nd warrior. I have seen a thread about this and I am wondering why they would take the levels in warrior? Just for the bonus two feats?