The rules on using monsters as PCs are blatantly contradictory, with the Core Rulebook using one standard and the Bestiary using a different standard.
Monsters as PCs: For monsters with racial Hit Dice, the best way to allow monster PCs is to pick a CR and allow all of the players to make characters using monsters of that CR. Treat the monster’s CR as its total class levels and allow the characters to multiclass into the core classes. Do not advance such monsters by adding Hit Dice. Monster PCs should only advance through classes.If you are including a single monster character in a group of standard characters, make sure the group is of a level that is at least as high as the monster’s CR. Treat the monster’s CR as class levels when determining the monster PC’s overall levels. For example, in a group of 6th-level characters, a minotaur (CR 4) would possess 2 levels of a core class, such as barbarian.
Monstrous Characters: As a general guideline, you should advise your players to choose races of roughly equal power, using a creature’s racial HD (not its CR) as a general guideline. Characters who wish instead to play standard races should be allowed to start at higher level, so that their total HD match the highest HD held by a non-standard race in the party.
The two quotes (emphasis mine) say very different things.
-Using the Bestiary rules, a Minotaur character (6 racial HD) should have two class levels (Ex: Barbarian 2) in a level 6 party, giving him a total of 8 HD.
-According to the Core rulebook, the standard-race characters should have total HD equal to the non-standard race, so a Minotaur Barbarian 2 (6 racial HD + 2 class HD) would be matched with a party of 8th-level characters.
As far as Racial HD counting toward character level, it's never stated that "racial HD count as part of character level," while it is stated "Character level is the sum of all of the levels possessed by a character in all of his classes." "Treat the monster's CR as its total class levels" is, I suspect, more relevant for a GM attempting to determine difficulties and level-equivalence in mixed parties than it is a statement that Racial HD = Class levels.