Nav/BC - How can i tell if an item has been successfully cost adjusted?

Check the Cost Is Adjusted field. 0 = No, 1 = Yes.

 select No_,[Cost is Adjusted] from [Cronus$Item] where [Cost is Adjusted] = 0

How can i tell how many adjustments need to be done?

The highest count ones should be done first

SELECT        CRONUS$Item.No_, CRONUS$Item.[Cost is Adjusted], COUNT([CRONUS$Avg_ Cost Adjmt_ Entry Point].[Cost Is Adjusted]) AS EPCount

FROM            CRONUS$Item INNER JOIN

                         [CRONUS$Avg_ Cost Adjmt_ Entry Point] ON CRONUS$Item.No_ = [CRONUS$Avg_ Cost Adjmt_ Entry Point].[Item No_]

WHERE        (CRONUS$Item.[Cost is Adjusted] = 0) AND ([CRONUS$Avg_ Cost Adjmt_ Entry Point].[Cost Is Adjusted] = 0)

GROUP BY CRONUS$Item.No_, CRONUS$Item.[Cost is Adjusted]

ORDER BY EPCount desc