With 20mg, I'd save that amount for bridging... If you're going to do a cycle with it, I'd up it to 35mg-40mg/day and run it around 6-8 wks.
You should start noticing strength increases within 5-7 days.... If you haven't had a chance to yet, do a search on anavar and you'll find some great threads on it that have been posted in the last week or so...