Emphatic YES!
Meter the areas where you want to photograph before the ceremony even starts with the same lights that will be on during the ceremony. Warning- weddings happen at dusk too! So if you meter at 4 in the afternoon and your wedding isnt until 7, the light inside the church/ceremony area will change.
Carry a note pad and write these figures down and with time you will be able to recall them without getting confused...its just a matter of practice and force of habit.
For portraits/formals out of doors an old rule of thumb is meter off of green grass, is supposedly has the same reflectance as generic gray....but if there is ever any doubt, take an indecent reading.
Receptions take place in dark, photographic black holes! If you dont have a flash with a thyristor in it, learn your guide numbers, zone focus, take a quick quick look at your distance scale, and adjust aperture properly-- stick camera in scene and say cheese...sounds like a long and cumbersome process, but it happens as quickly as you can move your fingers (in moments) if you are are able to manipulate your camera's aperture ring without having to double check every 5 seconds.
If your flash does have a thyristor circuit in it, your job is made that much easier, point, focus, shoot...again Warning: technology is fallible. My Nikon SB26 has this convenient feature but consistently over exposes most common reception images by 1-1.5 stops due to the black-hole like atmosphere of dark reception halls....a trial run would be best before wasting a client's money.
Hand held meters- Sekonic all the way- you can get them dirt cheap used, but still its worth spending $133usd for one new if you intend to use it more than once. Granted you could spent $600 and get a mac-daddy sekonic, but you would have to have a legit need for such an investment.
All the best and good luck with your wedding.