Unfortunately I have never been to Munich, so I am no real help. I'll try anyway. ^_^;;
So, there is a really, really, really long article on Wikipedia which basically lists all sights to see. It kinda depends on what you want to see. From old churches to Shoping malls you can find everything you wish. Maybe there is going to be an interesting tradefair when you're around. Or maybe you can find an interesting theater play. I even guess that there are some cinemas showing movies with original Englisch audio...
I guess it mainly depends on what you want to do.
And some of the following links might be helpful for you:
Munich tourist information:
http://www.munich-tourist.info/
Sightseeing Tours by bus:
http://www.citysightseeing-munich.com/
The site of the city itself, allowing you to browse city life, tourism, business and shopping:
http://www.muenchen.de/home/60093/Homepage.html
contact addresses for the tourist information:
http://www.muenchen.de/Rathaus/raw/Tourismusamt/angebot/118244/Touristinfo.html
And last but not least:
A sight that might help you to make up your mind where to stay:
http://www.muenchen.de/Tourismus/Accommodation_Hotels/hotel_reservation/76390/index.html