Planning

Danny and I are going to London in April.  Ashlyn is already there and we will join her for ten days.  We get to see her graduate from her fancy pants design school and then it is the three of us in London, Baby. 
Ashlyn has been there since January and has already hit the town.  She will be able to direct us towards some of what we definitely want to do and steer us clear of the tourist traps.  Always the trooper, Ashlyn will go back to the sights with us!
Now here is the problem.  Or problems.  Problem number one is that I am trying to plan this trip with Danny.  Danny is great to travel with.  He carries the heavy bags.  He lets me sleep on his shoulder.  He... ok Danny is great to travel with.  We always have a blast (except in Bamberg) when we travel but trying to get that guy to focus on the planning has definitely been a challenge.
We have ten days.  Now the tour company rep thought that was a long time to be in London, but when I start flipping through my London to do book, I cannot figure out how to get it all in in ten days.  So when I try to corner Danny on what and when we are going to do what and when, I usually get some sort of vague reply.  Last time, I got a raised eyebrow and an "ok!".  We got nothing planned.
So where do I start?  I am asking for, begging for suggestions.  I have a travel book.  I have a list of sites saved in my favorites.  I have time, but not a lot of it because before I know it, it will be April and I will still be trying to plan this trip.  So...
Tomorrow I should buy a giant white board.  I should sit Danny down at the dining room table and make him focus on this trip.  I should. 
Or I should just pack my bag and show up on Ashlyn's door step and let her show us the sights!