Does anyone know how to join a library here? And whether there is a library which has some english books available?
There are several libraries in the city which have English books - have a look here
To use the university library you will need your passport plus your student ID
The Munich State Library charges an annual fee for membership and you need proof of residency and ID to join.
I wasn't really expecting a positive answer, so this is brilliant. Thanks for taking the time to reply.
If your are a book lover and you haven't already been there you should visit the Munich Readery - it's a gem! A great book shop but they also do lots of special events including author readings and storytime for children http://www.readery.de
Amerika Haus on Karolinen Platz has a library with books in English plus newspapers and magazines - good place to go for browse!