The archive search engine is a fairly straightforward affair, but you can do some pretty detailed searches with it if you use it right. Enter as many keywords as you want, seperated by spaces--if you want to group two words together, like "Myth netmaps", use double quotes.
Then tell the engine whether you want stories that match all of the keywords you've given, or any of them (or none of them, if you want to exclude something). You can also tell it where to limit the search to, so you can search only the headlines of Marathon related news items if you want.
And that's all there is to it. If you don't care for such fine detail, just use the default settings, which should yield pretty good results, but be ready for lots of hits...