Change the number of trained skills to a number of skill points, and 5x that at first level. It costs one point to improve a class skill, two to improve a non-class skill. The max rank of a skill is (your character level+5).
At every 5 ranks in a skill, you receive special benefits of the skill. Universally, at 5 ranks you are considered "trained". This is important for several species conditional bonus feats or feat prerequisites.
You gain 5 skill points.
You gain a skill mastery bonus for one skill your trained in.