How to get full 360 sphere angle for accelerometer?

I've got a couple of projects at the moment that are using accelerometers and I have them reading in degrees perfectly well in a half sphere but I would like it if I could get the full 360 degrees on both axis to get data on a full sphere of rotation; I've been told that rotation matrices and the direction cosine matrix are ways to do this but I haven't found anything that explains how to do this particularly well.

If any of you know of a good guide for how to do this or another route for getting the full range of data for an accelerometer I would appreciate any advice that can be given.

Thanks in advance and all the best

This is the most comprehensive and the clearest treatment I've seen. It deals with all the complications quite well. http://www.freescale.com/files/sensors/doc/app_note/AN3461.pdf

I didn't see any info on what accelerometers you are using.