Winter sowing is a method of starting hardy seedlings outside during winter. This site, constructed by one of the method's gurus, documents which seeds are amenable and how to go about it.
Bonsai enthusiast Brent Walston explains the fundamentals of germinating woody species, emphasizing the requirement to break down germination inhibitors.
Sexual propagation by seed and spores and asexual propagation by separation and division, cuttings, layering, grafting and budding and micropropagation/tissue culture.