Ed, we used
Kodu. They have a series of lesson plans and videos already done
so it becomes a self-paced club. Other tools we are using are Scratch, Blender, Unity and pencil. Autodesk is another one, we use this at high school. Khan Academy is another good one, and Google has a coding series as well that incorporates some of the above apps.
I would recommend having the students write out what they want to do first so that have a path to follow, otherwise it is easy to get lost. I like Kodu and Scratch for beginners because it focuses more on if-then statements and helps students see the progression. These are transitional programs into the CSS, C++, Java and HTML coding students will get into later.
Mickey