On the second Saturday of each month, Lowe's hosts a building workshop for children, free of charge.  I believe it starts at 10 a.m. and lasts one-hour.

On the first Saturday of each month, Home Depot offers the same sort of workshop between 9 a.m. and noon.  (It only lasts that long if there's enough interest.)

These are free programs and great for both genders.  Free aprons and eye protection are usually included and available for take-home.  Certificates are personalized and offered at the end for successful completion of the project.  Lowe's gives a patch and a sticker.  Home Depot gives a pin for clothing.  These are fun to collect and/or scrapbook.  Take your camera . . . it's a hoot!