After you're married, your fiance will need to apply for FLR, which is the equivalent of the spousal visa. The fee is £500 in person (Birmingham, Croydon, Liverpool, Glasgow) or £335 by post (could take up to a month according to experiences posted here, though the website says it could take more than two). Once he has his FLR, he can work.
You can honeymoon within the UK following the wedding, but your fiance won't be able to leave the UK as he'll be entering on a invalid visa (i.e., he'll be a spouse trying to enter as a fiance).
If you plan to apply for FLR in person, it's a good idea to start calling to see if you can set an appointment now. Liverpool let me make an appointment for ILR a month in advance, though others have had the PEOs tell them they only take appointments two weeks in advance.