Looking for a service manual which will give me step by step instructions, so I can repair my own 02 A6 3.0L

Have seen quite a few options and want to hear from you, Audi experts, your recommendation.

Factory Manuals
Repair Surge
Bentley
Chilton

Thanks for all of your help in advance.

P.S. If you have a manual, can you share an article (i.e. replace valve cover gaskets), so I can see how easy it is to use the manual?