Here are some articles/photos. Can't find any video as yet.

http://www.members.shaw.ca/hydahlia/Pollinate.html

one more
http://hordeum.oscs.montana.edu/home/documents/methods2.htm

interesting written interview with some well-known hybridizers
http://www.kesdahlias.co.uk/raiseabestseller.htm

and one more

http://portlanddahlia.com/DahliaCulture/Breeding.html

Here is a link that might be useful: Wynne's pictorial pollination process

Thank you, Poochella, I really like the articles, but I cannot see the pollen from some of the dahlias I have. Do I take out the petals and look for the pollen? How do I know which ones are ready to receive the pollen and which ones are not?
Thank you for any more articles that you can give me, regarding the actual pollination.

Someone else who actually does these things will have to answer. I just grow them for the flowers but am always grateful that there are people who take the time and effort to come up with fantastic new varieties every year.

Wait until the bloom goes to center- then you will be able to see the pollen. Don't pull the petals out of the center or you will remove the pollen bearing stamens & then you won't get any pollen for sure! Look at the pictures on our site that Poochella posted to see the process. You can remove petals at the back AFTER the bloom has gone to center- this esp on AA & A sized ones so that the petals don't rot & ruin the seed pod. There's step by step pictures of what to expect from a pollinated pod, how to dry them, etc. Be aware that you won't get a seedling that looks anything like the seed parent- they have a very complex gene structure like people do & so no 2 dahlias will be the same- too many combinations of genes possible.
The parent is ready to receive pollen when it goes to center & it's stamens & pollen show.

Thank you plantlady. It does make sense now. I guess, I have to wait till the bloom goes to center. Oh yes, I have seen the process in your site and yes, your site is very helpful.
Thanks again.

I'd just like to add a word of encouragement to anybody planning to hybridise dahlias (or just to grow them from collected seed, hybridised by the bees!) You might end up with some duds, but you are also likely to get some garden-worthy plants. It's really exciting waiting for the first flowers to open. Rewarding too, because they will flower in their first year and will continue to improve in successive ones. I have a bed of dahlia grown from saved seed and will post pictures once they start flowering.

The bees do a much better job of pollinating dahlias than people. As with any subject there is the short answer and long answer. Short answer: Let the bees do it and limit the dahlia pollen they can use by cutting off flowers and planting the ones you want crossed close to each other. Long answer: Hand cross two flowers that have been covered by an old nylon stocking. Since bees pollinate several times per day over the course of a week or more, you must pollinate numerous times. Lot more to it, but if you do this and get some seeds that sprout from covered flowers, you know both the parents of your seedlings.