Originally Posted by botto
4 days on, 1 day off is one way to go about it. There's tons and tons and tons of good advice buried in the archives here, so I'd recommend doing some research there.
One small piece of advice - don't repeat you're distance or intensity every day.
+1
If you do the same intensity and distance, your body will become accustomed to that.
If you want to get faster, I'd also recommend getting a day of intervals in there, followed by a day of either active recovery or rest.