There is no ledger, there are just transactions with inputs and outputs. Your bitcoin balance is the sum of all the outputs to addresses that you own that haven't yet been used as input to another transaction.
I think a comma is helpful to disambiguate that last sentence. (though It's still potentially confusing)
"Your bitcoin balance is the sum of all the outputs to addresses that you own, that haven't yet been used as input to another transaction."
I wouldn't know how to phrase it any better.. but for someone trying to get to grips with the concepts it could read as either:
Your bitcoin balance is the sum of all the outputs to: "addresses that you own that haven't yet been used as input to another transaction" (wrong interp)
vs
Your bitcoin balance is the sum of all the outputs (to addresses that you own) that haven't yet been used as input to another transaction (correct interp)