Yes.  It's fairly easy, actually.  You have a few options.

First, read up on parameters.  Both in the help file, and in Brian's book.  That will answer a goodly chunk of your questions.

Now, you have three basic ways to get the date window you are looking for.  You can create a single date parameter, that represents either the beginning or ending of the window.  Use DateAdd to calculate the other endpoint.  You can create a pair of date parameters, which are the endpoints of your window.  Or, you can use a daterange parameter, which is a parameter that includes the entire range of dates.