So I am going to make one of my external drives wireless and use it for TimeMachine. I will hook it up to my wireless router and then it will be a "network drive."

Since I already have data on it, as a TimeMachine back up and a small partition for CCC, will it pick up where it left off or will I have to start over?

Also, I have another external drive as a back up, back up...and Would I be able to plug it in and use it with TM? or will TM automatically go to the network drive?