We will be using the Pathfinder rule system. It is very similar to Dungeon and Dragons v3.5 with a number of balancing tweaks. Online reference copy of this amazing system http://paizo.com/pathfinderRPG/prd/ though I highly recommend the system. But online link is nice for looking up rule/class changes when you don't have the book handy.
Each section of wiki has changes relating to that area. The following rule changes are worth calling out however:
Caster level requirements on all permanent (non-charged) magical items are Arcane caster levels only. Divine casters can make potions, wands, scrolls but not weapons, boots, rings, etc. This is partly to explain why arcane casters are still tolerated by society.
Feat - Because of the limits to magical crafting "Master craftsman" feat is much harder to attain. It requires 10 ranks and 50 years of crafting experience. The crafting process is more onerous as magic is from natural phenomena and rare ingredients but items crafted in this way are permanently sealed.
Skill - profession law-enforcement is useful for ministry procedures and codes.
Adventures are not going to have much "loot" instead you will have salary and be given access to nicer equipment over time using approximately the same scaling curve.