The content of the invitation was a joint effort between me and my husband.
My husband happens to be a really excellent writer and an extremely literate person. So I wrote the first draft and he edited it.
We sent out an email invitation through evite.
It is free, and it tracks the number of responses and attendees. It is also fun because depending on the privacy settings, people can post comments and see who else is also coming.
It kind of helped to build excitement for the event.
The only other caveat is not to overlook anyone. If nothing else, remember to invite anyone you are going to see on a regular basis!
Some people might hold a grudge if you forget to invite them. I personally recommend being as inclusive as possible.