How can I get a graph, by day, of the standard stockmarket parameters
from three months ago until today?

Bigcharts.com (the service used by Etrade and CBS Marketwatch, among
others) will quickly allow you to generate the chart you require.  If
you follow the link provided, simply change the "Time" indicator from
"1 Year" to "3 Months" and click the "Draw" button.  You can leave the
"Frequency" unchanged, as it is already set to "Daily"

By default, this will draw a chart that shows the Hi-Low-Close and
volume for each day in the period.  Other options are available.

Dow Jones Industrial Average Interactive Chart:
http://bigcharts.marketwatch.com/intchart/frames/frames.asp?symb=DJIA

I hope that helps.  If you have additional questions, please do not
hesitate to ask for a clarification.

What better answer to this queston might I expect?