I want to find the number of searches, Google users undertake for
specific keywords. I.e. how many times has Google been used to search
for 'jobs' today? Its important to get the information for the current
day or the past 24 hours. I want to know the algorithm to find the #
of searches for any keyword. Please don't point me to any software
application which may be creating those results, but tell me what I
have to keep in mind from the business process point of view if I
built such application myself. Great thanks.

It is not possible - Google does not make such data available to the public. 

I use a combination of Google Adwords - run an ad for a keyword and
you will see how many impressions it gets each day, and the Overture
tool.

robertskelton-ga
Google Answers Researcher

You can use overture to determine this. Visit
http://inventory.overture.com/d/searchinventory/suggestion/ and enter
a particular search query. It will include search variants.