Distance - HELP ME!

[the real findorfin]

I'm trying to create a fantasy trilogy at the moment and the distances are killing me.
I've drawn a map out but as I haven't a clue as to how far horses/men can travel in a day, I've had to scale it in to 'days on horseback', which is very difficult, (and rather stupid sounding now I've typed it out).
But its the only way I can do it.

Is there anyone out there who has a good knowledge of distance, for instance:

daily distances of...

Horseback travel, not a dash but quite urgent
Horseback travel, devil on your back speed
Walking, every second counts
Walking, making your way across country, but at a moderate pace.

Any help on the things I've said, or any other ways of travel would be MUCH appreciated.

THANKS