Being a very new 1150 GS owner myself I have spent hours on the net trying to get all the answers. Sometimes you end up getting much more confused, but a manual is always a good start to any problem.
Link to 1150 GS repair manual:
http://www.scribd.com/doc/7179043/BMW-R1150GS-Repair-Manual
It is no less than 311 pages and includes loads of useful info, and some less useful info as well, but there you go. It is hopeless to use in your browser but can be downloaded (after being taken through some options of uploading stuff yourself, where you just click no thanks) - the file is about 50 Mb!
You will find "Tightening torques" on page 5, but they also specify tightening torques in each specific chapter.
Hope it might work for you - it has for me