This is a must-do, especially if you have the Museumkaart! I went to three different canal houses, and W-H was my favorite. DEFINITELY spring the 2 Euros for the audio tour, which is comprehensive, detailed, and very interesting.
Plan to spend an hour or so in the house - you won't need much more than that, unless you spend a long amount of time wandering through their collection of miniatures.
What can you expect to see? The gorgeous rooms, staircases, furniture, wall paper, and beds that you would have seen around this time. The kitchen area was also fascinating, and will certainly remind you a bit of your history reading (or Downton Abbey).
So, don't pass this up because it's not the Rijksmuseum. Check it out - you'll enjoy it!