Here's the old post office. It's on the tourist information 'must see' list. Melk, one of the only places that I found where a post office, bakery, and shoesmith are on 'must see' lists. Melk really is a nice, but possible overtouristed little city.
This is the inside of the Stift Melk library. I believe it housed over 17,000 books, it might have been 70,000 though. It was really elegant and covered in a ton of gold.
The Stift Melk, you can't miss it. The city of Melk is famous for it, and it's so brightly colored and highly perched that it can be seen through most of Melk.
The cafe rathaus was pretty good. It's right in the city center, you can't miss it. Melk is a pretty small little town so I'd imagine just about every little place it pretty good to eat at.
Favorite thing: Visit 'Burg Rapottenstein', a picture-perfect medieval castle, well preserved and secluded from the masses of tourists...