Guide or Recipe for DataAssist working with Joins?

Need to have my detail page suggest other products the viewer would 'like', unique to each product. I plan to have a secondary table with the primaryID (the current detailed product) and a secondaryID (multiple products listed). I know on the detail page I'll need to do a join and pull a second recordset based upon those fields.

I'm just not sure how to do the dataassist insert and update page so that the client can list part numbers for the 'like' items and have it write/update both the primary product record and multiple 'like' records for the secondary table.

Is there a Recipe or some type of guide somewhere that would walk me through that setup process?