VLookup question

Hi guys, I am after a bit of help from those in the know again if possible.

I have been asked to compile a database at work, what I want to do is display a sum value of figures from a table if the date falls within a specified range.

This is based on invoices so I could have for e.g

10/12/08 - Inv3874 - £1000
13/12/08 - Inv7264 - £6000
16/12/08 - Inv5636 - £2000

I am trying to get a formula to display this within two adjacene cells on a sumary sheet

e.g.

Dec-08 / £9000

The Dec 08 I would input myself

I have a similar one which I calculated number of invoices for which I used:
=COUNTIF('Input 1'!D:D,">="&DATE(2008,10,1))-COUNTIF('Input 1'!D:D,">="&DATE(2008,10,31))

would this need to be included, not sure if I should use sumif?

Any help would be much appriciated

Thats excellent, thank you very much for your help!