If you want to use todays date, try making a batch file like this:

set d=%date%
set ff=%d:~0,4%%d:~5,2%%d:~8,2%
for %%i in (dsc*.jpg) do ren %%i %ff%%%i
set d=
set ff=

It will used today's date to construct a string like 20071216 and prepend it to the file name.