Advancement in EIB is not linear; there are no "levels", per se.
Instead, you will be spending earned experience points to increase your dice pool in any given skill or ability.
Costs
ATTRIBUTES:
To add a +1 pip to any attribute, multiply the # of dice in the attribute pool x 1000 and spend an equal amount of experience.
IE - Wulfric has 3D agility. To gain a +1 pip to his agility, he must spend 3000 experience to make his agility 3D + 1. He must then spend another 3000 experience to make it 3D+2. Upon spending the last 3000 experience, his agility will become 4D, and to increase he will need to spend 4000 experience.
SKILLS:
To add +1 pip to any skill, multiply the # of dice in the attribute pool x 500 and spend an equal amount of experience.
IE - Wulfric has 3D in Bows. To gain a +1 pip in bows, he must spend 1500 experience to make his bows skill 3D+1. (etc, etc.)
NOTE: "Specialized" skills cost 1/2 the price to raise. For more information on "specialized skills", please see the Minisix rule PDF.
LEARNING A NEW SKILL:
To learn a BRAND-NEW skill involving some form of technical expertise, the character must first find an appropriate teacher or mentor to learn the skill. The experience necessary to learn the skill is 500 exp, as well as any applicable costs in gold/time.
To SPEND EXPERIENCE, make a post in this forum (Flesh and Blood Grimoire) referencing exactly what you're spending it on.