Music

There is an abundance of record stores in Cologne, but most are hidden in non-tourist quarters.

For a mainstream record store, go to Saturn, which hosts the "world's largest CD collection", as they quote on their store windows. It's huge, and to pre-listen a record, you just have to hold it under one of the many scanners spread throughout the shop. Always worth a visit. Subway and Regional Train from central station: Hansaring

Independent record stores are spread around Saturn: Cross the street for 2nd hand and punk, follow the "Ring" (boulevard) north, and you will find Jazz, Electro and HipHop at Schallschock record store. Famous alternative music-store Normal is south of Saturn, as well as Underdog Record Store (specialized in Alternative Rock, Emo, Garage and related matters) Subway and Regional Train from central station: Hansaring
For electronic music, get off at Friesenplatz, and go to groove attack in Maastrichter street. Also famous is Kompakt record store. Both are connected to a label sharing the name, and putting out fine German electronic music. Subway: Friesenplatz

Clothing
For mainstream shops, go to metro station Neumarkt or Heumarkt, and search for "Schildergasse". More expensive shops are found on "Hohe Straße".
A mix of freaky 2nd hand stores and places selling hip label clothes head from Neumarkt to "Friesenplatz" and go to Ehrenstraße, Apostelnstraße, Breite Straße.

Books
"Mayersche" and "Thalia" at Neumarkt are the biggest bookstores, you will find anything you want.
On "Ehrenstraße", you will find cheap and arty books, take a look at "Buchhandlung König" at the eastern end, buy art books at weel known "Taschen" at the corner of Ehrenstraße and the Ring.
Travel books are bought best at "Gleumes", between Zülpicher Platz and Rudolfplatz. They have only maps and travel books, but these from around the world.