Mind you, I'm no expert, but the cocks are ready to play at about 6 months and, judging by my young hen, the hens at about the same age (maybe a little later).
I, too, use a mixture of pine & cedar chips, and a bit of timothy grass (with some tobacco stalk thrown in for the birds to build their nests with)....with a product sprinkled underneath to ensure absorption of fluids. My floors are wood - lined with the rubber sheeting used for lining an outside pond tacked in place. That way I can easily sweep it out and hose it down for cleaning. There are many here, however, who have cement/concrete floors and do not use any bedding.
Saw dust is too dusty and can cause respiratory problems.
My birds started pairing up before 6 months, but it is better to wait until they're a year or close to it before letting them breed. Too young often don't make good parents. They're still babies themselves.