"Count" and "List" functions across sheets
 

I have 30 to 60 sheets in several workbooks. I need to do some "drill down"
analysis and reporting:

I want it to count specific cells in all sheets that meet certain criteria
(e.g., b4<k2, count if blank, count if zero, count if J10 displays "overdue",
and so on).

Then I need it to look across the same sheets and list the numbers in B1
that meet the above criteria.

I've tried lost of permutations with Insert Function and Countwhatever, but
all these formulae come back as zero or invalid or "#Value!" or Excel says
forget it try again.