Well, a couple of thoughts.
One is to know the skills you need compared to the skills you have. You haven't told us about the nature of the day, but assuming the typical, it means a dark church followed by a darker reception. How are your flash skills, for instance?
For the ceremony, you need fast lenses that focus quickly. The 50 1.8 focuses very slowly and is really not up to the rigors of wedding photography. Leave it home and use your 24-105 nearly all day. For the processional, shoot around the middle focal length range. That coupled with f4 should get you enough DOF to use one shot. Also, you're typically allowed to use flash for the processional and recessional and you should. Stay in the aisle, try not to be intrusive, and get what you can; sometimes shooting wide sometimes long.
The reception can be fairly easy if you don't allow yourself to complicate things. I now use AB's and triggers to raise the ambient plus an on-camera flash and the look is nicer. However, I shot all of my previous weddings with a single on-camera flash bounced off the ceiling plus a large bounce card and they still look great. Shooting a wedding is not the time to experiment and practice so go with what you know. Keep it simple and allow yourself to stay mobile.
The couple should plan the list of group shots they want ahead of time. Technically and creatively, these are very simple photos; keep them that way. It's mostly just a matter of organization; having that list as well as the help of someone to gather the poeple for you.
Finally, the biggest deal is simply knowing the flow of the day and not allowing yourself to be surprised. Attend the rehearsal so you have some sense of the ceremony. Visit the reception venue so you know what you're working with and any challenges it presents. Consider where you'll shoot portraits if it rains. On some level, planning is more vital than gear and technical skills.
Also, there are some stickies in this forum that would be helpful for you.
