Maximum skill points per skill is based on your overall Class level, so 6 points max per skill for your Fighter 2/Alchemist 4.
say i am lvl 6 and i am a lvl 2 fighter and a lvl 4 alchemist. anyways how many skill points can i put into the skill is it based on lvl? or based on class lvl? can my character have 6 skill points in a skill or 2 and 4 based on the class the skill is attached to.
From the PRD: "You can never have more ranks in a skill than your total number of Hit Dice."
Hit Dice means your total character level, so you can have 6 skill points in a skill.
In PF, there is only one difference between class skills and non-class skills: class skills give you an additional +3 bonus.
That's it. There is no limit on the choice of skills you can invest ranks in, aside from the total number of skill points you get based on your class and your INT bonus. Maximum skill ranks is your character level (the total of all class levels for multiclass characters).
Much simpler than DD3.5.
Yeah, you can forget a lot of little rules from 3.5.
More than anything else I find the more mistakes that occur in Pathfinder occur because "people knew how it worked in 3.5".