The core of Cub Scout advancement consists of “Adventures” in each Cub Scout Handbook (if you don’t have a handbook yet, you can order from the BSA ScoutShop). 

To help den leaders and adult family members deliver these Adventures, there are a variety of resources including Den Leader Guides with activity plans for each Adventure.  

All of the 95 Adventure plans and resources are available at “Every Cub Adventure (95+) - Cub Scouting Advancement Resources to Help You Do Adventures At Home”.  There are pages for each of Bobcat, Lion, Tiger, Wolf, Bear, Webelos and Arrow of Light, and within those pages, separate “Adventure by Adventure” pages of ideas for when families lead an Adventure. 

For example, if you want to do a Science Adventure, you could check out "Air of the Wolf", and find the requirements, the Adventure Plan from the Den Leader Guide, plus other tips that have been found on sites like Scoutshare and many Council Websites. 

Then, look at the other 94 sites -- there's similar pages for each Adventure at “Every Cub Adventure (95+) - Cub Scouting Advancement Resources to Help You Do Adventures At Home”.