When my kids were little, they loved going to the Home Depot Kid's Workshops. They had the bird house, mail box and tool carrying case they made at the clinic for years. I think we still have the apron with their name on it that they got that day.
Home Depots offer their free workshops on the first Saturday of each month between 9am and noon. You can check for your local Home Depot on their website.
Lowe's has gotten wise and are offering similar workshops called, "Lowe's Build and Grow Clinics." They are offering their clinics on the 2nd and 4th Saturdays of the month.
These free activities are a great way to teach your kids about how to hammer a nail and make a simple wooden "something." The wood is pre-cut and the instructions are easy... but the kids DO have to put the project together. A great parent and child activity. The workshops are geared to kids between the ages of 5-12. The materials, safety glasses and aprons are free.
I do suggest making sure that your local Home Depot or Lowe's is having a workshop on the day that you plan to attend. Also, preregistration and early arrival are wise.
Of course, if you can't get it together to take your little loved one to the store, then you can just buy the Home Depot Ready-to-Assemble Kits and the Lowe's Kid's Starter Tool Kit online. Then you can have some cool parental and child (non-bargain but cool) quality time in the comfort of your own garage.