How do you attach a ledger to the house?

The only problem I'm having with building my deck is the ledger. I don't have access to the the other side so I'm not sure what I should use to attach the ledger to the rim joist. Also how do i know where exactly where the rim joist is locate? Should I cut until I reach the rim joist or right before because there is also foam board insulation under the siding? Also how do I attach flashing if the ledger is deep into the siding because of the insulation? sorry for all the question. I've been putting it off because I can't find how to do this with my situation. The rest of the deck is no problem.