Sorry Sam, just noticed this...
First thing you say (so long as nobody else has beaten you to it) "Ladies and gentlemen, isn't she absolutely beautiful!". And you've got a round of applause as soon as you've started - big confidence booster.

- I need to acknowledge both the bride's parents, both sadly absent
Hmm, if you haven't already, I'd ask her about this. We're talking about a happy occasion and she may not want you to dwell on sad thoughts. If she is ok with it, keep any references brief.
When my eldest was married, her gran had just died, and the groom's dad hadn't been long gone. Both of them were very much of the "leave it out" opinion, and were grateful that I didn't refer to such things in my speech.
I'm (apparently) supposed to recount an amusing story from the bride's childhood - I've asked my wife, who is struggling to come up with anything!
Make a couple up (or make some old classic jokes fit). Seriously. I've lost count of the wedding speeches I've witnessed where the truth is sacrificed for the sake of a laugh. I have horrible recollections of one of my best man speeches where I was recounting a particular "true" story which I thought was hilarious. Not a titter was heard. You had to be there I guess.

Find a couple of old (preferably unflattering) photos and get them enlarged so everybody can see. That one always goes down well.
Other bits of etiquette I'm not sure I'm yet aware of
Just be your old charming self Sam and you'll be fine. Get some source material for a couple of one-liner jokes - do an internet search on Tommy Cooper, Bob Monkhouse, Billy Connolly etc Don't try to reinvent the wheel. People don't care if they hear old jokes, they embrace them like long lost friends.
Slip in the sincere bits at the end - they always gets the "ahhhh"s that the ladies are desperate to emit. You know the sort of stuff...
When my old pal was (re)married last year I managed to get in an "ahh" and an insult in the same section. I said (paraphrase) my pal turned up with this pretty lady and I immediately thought there must be something seriously wrong with her, then as I got to know her I discovered she was "as beautiful on the inside as she was on the outside". - got a round of applause for that
A popular toast of mine is the stomach turning "Love, laughter and happy ever after". Amazing how people lap up stuff like that

Feel free to use/ignore any/all of the above. As I said, be yourself - I bet your speech will be excellent.