Georgineer, thats a very good point and story, hopefully a few old boys will tune in and it'll make them think....if you're leaving the business to someone you care about, its should be done with the view when the time is right for both of you.
I've some experience with transaction business sales, M&A etc and boy, the answer to the OP's Q is a book It's probably like that famous AA line though; recognizing it as a concern is half the battle. Most people don't like to face their own demise, and a lot of entrepreneurs have this psycho everything is a state secret approach....so if you can get Dad on board that its something to openly discuss and work on, yeah, you are probably half way there. If Dad's talking, congrats.
I've come to the conclusion that buying private businesses is 2% financial and 98% psychological. What i mean be that is the the owner thinks its a dollars and cents thing, but really the most challenging part is when he realizes this job, this company is his identity and how massive (scary) the life change will be not being the man anymore. I don't think succession is much different insofar as the psychology involved plays a major role in Dad letting go. Be aware of that; make sure there's a role for him afterward, that he'll still be valued, needed etc. A deal starts off all business and finance but dies when the owner realizes he's not selling shares he's selling his identity. Vertigo sets in. Same psych applies here i think.
Accounting firms have put a lot into succession planning as its a hit issue with the baby boom bulge that will be wanting to retire. Lots of clients who don't understand succession planning and need help. Talking to a decent account firm might be a good start. The one thing they will all say it is a process that should start years in advance which is true
No one size fits all, but guiding principles might be planning and professionalism. What I mean by professionalism is, insofar as deciding what to do, forget its family and think of it as a third part sale of a business. The son/daughter should approach it as if they are buying a business; how will they ready themselves? What skills will they need that they don't have? should they go back to school, learn accounting, learn finance, learn sales, what areas of the business do they know, where are they weak, should they work outside the firm, obtain certain degrees or certificates etc etc....the kid has a responsibility to be ready to do an even better job than Dad did and Dad wants to see that as well or he'll be nervous handing the reigns over.
The parent should approach it as if they were readying the business for sale. This takes years but is basically putting the house in order, cleaning things up and documenting the business. Making sure there's a team and process in place such the world doesn't revolve around the owner. It is a process readying a business for sale (to maximize its value) and that same process will make for a smooth transition.
Lastly, you need to plan for relationship transfers. Think this through and do it slowly. In most businesses there are external relationships that are meaningful or even critical to the bottom line - planning on this transfer is part of what you'd do for readying a business for sale. While the business isn't being sold in this case, follow the same methodology; failure to do so would impair the value of a business when its being transferred (whether sale or succession). For example, if you were reading the business for sale, over a period of years shift key customer relationship to managers other than the entrepreneur - in the case of succession make the prodigal the transferee. You can't transfer a relationship over one lunch, plan over time how to get the successor interfacing with the people and trust will be built.