Tourist Entry Visa for China & Hong Kong - visit dates 23/12/2011 - 05/01/2012

British passport holders can stay in Hong Kong for up to 180 days without a visa, so you don't need to apply for a Hong Kong visa. Just make sure your passport will be valid for at least 210 days upon the arrival date to Hong Kong.
It usually takes 4 working days to process a visa.
Single-entry tourist visas to China are OK for you and your husband. Both of you should apply for a tourist visa.
The documents you need to provide to apply for the visa: passport; one recent passport photo; visa application forms V2011A and V2011B; UAE resident visa valid for more than 6 months; copies of the data pages of your passport and UAE resident visa; no-objection letter from your company stating your monthly or yearly salary; an invitation from CHINA travel agency; round-trip air tickets.
Injections or certificates? Do you mean physical exhimization certificate? It is not required from short-term tourists. With the tourist visas and pssports, you and your husban can enter China with no problem.