Christina Phillips takes a look at the difference between setting up journal posting per transaction or per batch in her newest post Posting Settings- Creating a Posting Journal Per What? up now at Dynamics GP Land. I’m a “per transaction” guy myself.
Posting Settings – Creating a Posting Journal Per Batch or Transaction
Archived post from 2010. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.