This is Gnus, so there are a number of ways of doing this. You can use the built-in commands to do this. There are the F and R keys from the summary buffer which automatically include the article being responded to. These commands are also selectable as Followup and Yank and Reply and Yank in the Post menu. You might also consider the Supercite package, which allows for pretty arbitrarily complex quoting styles.
Some people love it, some people hate it.
If you don't subscribe often to new groups then the easiest way is to first sort the groups and then manually kill and yank the virtuals wherever you want them. Any good suggestions on stuff for an all. Here is a collection of suggestions from the Gnus mailing list. I like blasting anything without lowercase letters. I would like to contribute with mine.