depends totally on the plant. For instance primulas and sisyrinchium are best sown in the green, before the seeds ripen. I always sow seed when it is ready, when mother nature intended it to be sown. Some seeds can be collected and saved. like Lupins. I don't grow annuals, but these are best saved for the early spring and sown in warmth. if you are saving seeds it is best to collect in dry weather. I have collected wet seed and left on a paper towel to dry out, but then this can be hit and miss. i always scatter a few seeds on the top of a seed tray, very fine seed i cover with fine grit, or a tiny bit of compost. Larger seeds can be covered with a little compost. But then some seeds need to have light to germinate. The best advise i can give is to check out two sites on the net.

http://tomclothier.hort.net/index.html or

http://theseedsite.co.uk/

both sites are a wealth of info, but they can be a bit fiddly on finding the info you need, but persevere with them.

It's a Chilean pine, probably a somewhat different planting method.

i entered Araucaria araucana propagation on the net and found this link.

http://apps.rhs.org.uk/plantselector/plant?plantid=4380