Hi Lou
You'll be flying out with Air China, who have a 20kg allowance per passenger in economy. Your hand luggage can weigh up to 5kg.
As for your flight times, you should receive your final documents about 3-4 weeks before departure, so if you haven't heard by, say, the week before Christmas, give customer services a ring on 01858 581980.
Kind regards
Olly, your editor