Not as easy as you might hope. The best alchemy equipment can't be found in an exact place in game, because it's only found as random loot in Necromancer/Mage dungeons at very high levels. Level up to well above twenty, then find every Necromancer dungeon you can, looking for Boss Chests. Boss chests are usually guarded by a boss level character, hence the name. Playing Oblivion for as long as I have, I only have three of the four pieces of Master equipment, so finding them may be very tough.