SPMC is the same as XBMC - you can either open videos that you've stored locally (so either in the Internal Storage of your device or on an attached USB device or memory card) or via add-ons. For a quick test of XBMC/SPMC, I normally go to:
System>Add-ons>Get Add-ons>XBMC.org add-ons>Video Add-ons>(end of list is quicker) YouTube>Install
Load up YouTube then, from XBMC homescreen>Video>Add-ons play a clip and see if it works.