SPM quick start
Quick start? Hahaha.
No, seriously - we may be able imagine something like that in due course.
For now, please see this nice document: http://ftp.fil.ion.ucl.ac.uk/spm/doc/QuickStart.doc
There are very useful practice data sets at the SPM site to start learning SPM. You could try following the SPM course lab book practical excercises to get a feel for SPM.
Of course, see also the SpmManuals, which include step-by-step guides to analyses.