Wiring a Detached Garage, Need Help.?

Danz pretty much got it, but you need a 6/4 conductor It is a Sub Panel requiring a Neutral, you will also have to drive an 8' ground rod outside the Garage for your sub panel in the garage with a #6 bare copper from the sub panel to your ground rod, If you use PVC Outside the minimum is 18" to the top of your conduit, if you use UF it's 24"......hope this helps