Hello Pambie.
Before I delve into computer based learning a question or rather a statement or two.
The term keyboard cover a very wide range, there are arrangers, pianos, synthesisers, workstations and permutations of them all.
Learning to play a piano is one system, learning to play all others is another system.
Now assuming he will want to get playing something as quick as he can an Arranger is often the route many new players commence with.
Arrangers are Yamaha PSR E463, Korg EK 50, and Casio CT X 3000.
Alternatively a digital piano can be Yamaha P125, Casio S1000, Roland FP10 or Korg B2.
There are many other models available but the above are the ones that I suggest you consider.
One piece of software to look at is called Flowkey which is aimed at teaching Piano, it is a subscription based system and a three month free trial comes with certain keyboards like the Yamaha P125. Another online system is Scoove.
Also check out pianogenius.com for a totally different way of learning to play a keyboard which is in a style more like you see and hear at a concert.
If you think about what I have written and watch video reviews of the keyboards it will give you an idea of what is available and it will give your Husband chance to narrow down how he wants to learn.
Finally do read my thread
Do you want to play a Piano or Keyboard? That is the question my Teacher asked when I took up playing keys after years with a guitar and bass. He qualified it by stating, there is a difference in how I teach you and in how you will develop. Piano. At its most basic level LH plays the Bass...
www.keyboardforums.com