Using iPod location services to find my way round new places

Question

I  like to use location services with map apps (such as OffMaps and MapsWithMe) to help me find my way around new places.
I understand that the information  ipod uses for location services,  the positions of various wifi transmitters,  is stored in an Apple database and that the location result is likely to be very approximate.  My problem is that I  cant figure out how and when the relevant data arrives in my ipod.  Typically it seems that when in a new town,  during my first wander round the place, the ipod does not know where it is -  locations will not be shown on these map apps.  On subsequent travels through the town iPod does seem to know where it is and displays its location on the maps quite nicely.  (But by then of course I  too know my way around and so don't need theiPod;s assistance so much to help figure out where I am.) 
So my questions are
1) At what point does the ipod get to store the crucial location information?  I'm wondering for instance whether the ipod remembers the SSIDs  as it encounters them, but only learns about their locations when it  is next connected to the  internet?
2) I'd like to know how much of this information the iPod can remember and for how long is it remembered.  (If I go back to a place visited last year will any of the previously "learnt"  locations be remembered by the iPod. I may well have forgotten my way round the place by then and the iPod's help would be useful)
3) Is it possible to "teach"  the ipod about  known wifi locations in a particular geographical area before visiting the area.  That would be a tremendous boon to me.

Answer 1

Good questions. However, I have never seen or heard about any information from Apple about how the iPod (and wifi-only iPad) really determine location.  I am waiting for answers from other users.