You might wonder what is better to level your paragon levels as a wizard:
This is a simple answer. You want to build your wizard out as an archon wizard with the highest DPS you can afford. From there you will want to test to see what monster power you can do really fast runs with. For instance in Act 1 the regular skeletons, meaning not the ones with shields or two handed executioners axes and certainly not elites or champions, should die pretty much immediately when you hit them.
Whatever monster power you are able to insta-gib the regular mobs on is the monster power you're most likely going to want to do your paragon experience farming at. Don't be afraid to play with the monster power, going up 1 level or even down 1 level, just to be sure you have the most efficient monster power for your current character abilities.
Make a note of how much paragon experience you have, how much you need for the next level, and what level you currently are.. just in case. From there I suggest you head into Act 1 and then out to the Weeping Hollow and clear the map. Don't feel like you have to hunt down and kill every single last monster, as that will often lead to wasting time which in turn leads to less than the fastest leveling. After you've done this a number of times on various monster powers you will know which MP level is going to give you the most experience per hour. Now you just have to do the runs to increase your paragon level!
Don't feel like you have to do full act clears. In fact this is usually not going to be efficient. Also don't play the game in story mode. Don't just start act 1, quest 1, and then play all the way through to the butcher, and then continuing on into act 2, and so on. You can if that's what you want to do, but we're talking about grinding out paragon levels here and nothing else.