One way you could use it is to just keep it handy to look up things when you or your children have questions.
Another way, might be to follow Ambleside Online’s nature study rotation and look up related topics as you go.
Another way would be to use it following Barb’s blog: http://handbookofnaturestudy.blogspot.com She has been posting challenges for a long time now, and they are listed in the sidebar. If you go back to the beginning she takes you step by step and gives suggestions as to pages to read and how to keep going.
Hope that helps. I’m not in a really cold climate to help with winter….
-Kim