When does pollination begin?

Im just wondering when males start attempting to spunk all over the females. Is it hard to destroy all the males and hermies before they succeed? Over all how difficult is a sensemilla crop to grow?

Also, is there a way to only pollinate one or two plants? The first crop I'll be growing is some low-riders ((needs to be a low-profile grow as much as possible)) and I know I'd like to have several seeded plants, but if I get like 8 females.. I'd really only want four or so pollinated.

Onnnnee last question. Can the pollen of a male plant be frozen and saved like most people do with seeds? And not that I care.. but I wonder if having weed-pollen in a container is illegal in the US. ^.^

Thanks for the help. ;)

if possible, separate the best male from the females, if you only want one or two females pollinated, put them in with the male you separated fromthe others. i stress you only use the best of both for seed propagation.
it is also possible to save pollen from your best male by freezing.
just make sure there`s no moisture in baggie you have collected pollen in. and freeze it.
you can take the baggie with the pollen in to seed your lowryder females you want, just take the baggie and place it over the plant you want pollinated. making sure all fans and air circulation devices are off, as not to disturb pollen, once baggie is placed over plant, shake it mildy to get pollen on female flowers.
there you have it, a few pollinated females. be careful not to disturb recently pollinated females so extra pollin does not get on other females

Thank ya much notanovice. :)