When to pollinate a Phalaenopsis?

[Laserbeak]

I have pollen I collected yesterday from a couple dying flowers from one phal and it's in a folded up piece of paper in a jar in the refrigerator.

Just today I received the plant I am going to use as the mother plant. It is huge with two giant spikes and the first flower is just beginning to open. At what point and which flower should I try to pollinate? Should I try to pollinate the first one to open as soon as it opens fully or should I wait for a later one?

Also will pollinating one flower affect the others? I know the pollinated flower should drop soon afterwards leaving the fruit (seed pod) to grow.

Thanks a lot! I'm a total newbie at doing this seriously with the hope of getting seedlings.