A good dataset of gene promoters come from the FANTOM5 project:
Their data is mainly derived with the CAGE technology, which sequences the first bases of a mRNAs.
RIKEN5 consortium. A promoter level mammalian expression atlas. Nature 2014 http://www.nature.com/nature/journal/v507/n7493/full/nature13182.html
RIKEN consortium. An atlas of active enhancers across human cell types and tissues. Nature 2014. http://www.nature.com/nature/journal/v507/n7493/full/nature12787.html
There isn't a genome-wide authoritative truth set. We know the absolute promoter and some enhancer sequences for some genes. We also have some evidence for where promoter and enhancer sequences may be based on things like DNAse I hypersenstive sites, transcription factor binding experiments, etc.