Hi Bill,
The journal header data should be entered in the journal upload screen (as you found in: General Journal > Import). Then a CSV is expected where the first line is a header line, naming these columns:
* accno
* debit amount
* credit amount
* source (= source reference number)
* memo (= remarks field)
basically, these are the same fields as you'd normally enter in the entry screen. "Source" is a reference to another system and the number the transaction line may have in that system.
The field separator must be a comma and the number setting (decimal and thousands separators) is the same as the one the uploading user has configured.
Off the top of my head I'm not sure if the transaction is immediately posted or should be confirmed by posting through the "Transaction Approval" menu item.