Am arriving from LHR (london) to PEK (Beijing) then transfer to CAN (Guangzhou). All with Air China

1. Your luggage will be delivered to Guangzhou directly. You needn't claim it at PEK. Anyway, make sure that you have the luggage check-through service of Air China at the departing place.
2. Upon landing, you need to go through Inspection & Quarantine, Exit and Entry Frontier Inspection, and Customs Inspection. Then, go through transfer formalities, accept Security Check, and wait for boarding. There are clear English guiding signs for your convenience. Don't worry! Have a nice trip! :)