You can type G-mail of the people you want to add 

Not one but together you can add many Gmail together and add them 

You can Notify people if you want , by checking the Notify people option

You can make them the Owner , this will not remove you from ownership, there will be two owners 

If you want to completely Transfer ownership , then there is a option for that too 

Either you are making someone the owner or you are transferring Ownership , the person needs to accept it 

You can type a message for them too