Alan,
I'm sure you will have a great time but I will warn you that there is virtually nothing of interest in VNG for someone who doesn't want to hear about port. You need to ration yourself on the lodge tours if you are to avoid the Gorgeous Deborah drowning you in the Douro
Most of the tours follow the same script. 20-30 minutes round the cellar with a tour guide who tells you what port is, how it's made, and why theirs is better than anyone else's. You are then offered 2 or 3 glasses of basic port to taste. Don't refuse as it may offend.
Like all good theme parks the exit is usually at the other end of a gift shop

Some charge a 2 or 3 Euro entrance fee and then discount that from anything you buy on the way out. Most are free entry.
From my notes of my trip a few years ago I remember Croft as being the most interesting lodge tour. Far less formal than the others and you actually get to see people working, not just a tour of what they want the tourists to see.
Graham's and Taylor's are a bit of a hike up the hill but worth the effort for the views alone. As you would expect from the big boys, they also put on a decent tour and selection of ports for you to taste. My notes from Graham's reveal 7 different ports before 11:0am
Calem is the first lodge you come to when you cross the bridge from Oporto. It's rubbish. Walk straight past it and cross the road. You can then have a nice steak and chips in an outdoor restaurant on the grass bank of the Douro
Sandeman do a good tour, especially if you pay a small fee for the special one which is longer, gives you more info and more samples
Ramos Pinto have a very nice museum that is worth a visit. A taste of the old world.
The Noval shop has strange opening hours but try to get there as they have the best prices I have seen anywhere for Noval and Nacional wines, apart from things like 1963 which get a bit on the high side.
According to the notes I took, Jo thought the tour guide at Taylor's was the best looking of the lot. Debs may like Taylor's

- My vote went to a lovely young lady at Croft. Pure coincidence that this was my favourite tour
Have fun
Derek