Calculating values from multiplesheets with multiple criteria

I'm sure this is simple nut I have no idea!
(Apologies for incorrect terminoligies)

*Background*
My workbook two worksheets of data.
I want to sum up the values of a range of cells, within a coloum, from both
of these worksheets into a new sheet and the values are based on more than
one criteria.

The info i wanted sumed is in $ format, the criteria in both worksheets are
the same and each worksheet will have a new row added almost daily.

*Example*
Problem 1-
On both worksheets:
Coloum I has a drop down list with two choices "Op" and "Inv"
Coloum J has a drop down list with choices as well "24501", "23120" and
"21005"
Coloum K has a dropdown list with choices as well "BucketOne", "BucketTwo"
and so on.
Coloum L has the value in $ format entered manually.

Question-
How do I sum up in a different sheet all of the values based on "Op" "23120"
"BucketTwo" from both worksheets?

Question-
How do I then seperate that info by the date I choose from say Coloum Z?

Question-
How do I E-mail the person identified in Coloum A that info automatically
when the date in Coloum Z comes around?

Summary
I am the most basic of excel user,so "dumbing down" an answer that even half
solves my problem would be greatlly appreciated.

Thanx