What you choose to write in a wedding invitation is partially determined by what type of wedding you are planning on having. If you are having a traditional first time wedding with all the bells and whistles, then you may want to add a little more than the basic information. If this is going to be a more laid back wedding or a second wedding with a not so traditional format to it, you may just want to list the basics.
The basics of any wedding invitation are the who, what, when and where of the event. A wedding invitation may also include the names of the parents, such as "Mr. and Mrs. Smith request your attendance at the wedding of their daughter Sarah Smith to Jeffery Jones..." with the date, time, and location to follow.
A wedding invitation may include a couple lines of poetry that reflect the way you feel about each other and your upcoming nuptials or a famous quote if it is fitting to your wedding theme. Whether you choose to use full names with middle name included for each of you or just your first and last names is up to each couple individually.
If you are planning a second wedding, the wedding invitation may look a little different. You may want to include your children's names on the invite to include them as part of the celebration, or you may want to create a more casual look and feel to it as this will most likely be a much more relaxed wedding or less formal than your first one.
It's important to note that it is not proper wedding invitation etiquette to inform if children are permitted at the wedding or reception on the invitation itself. This information belongs on the outside of the inner envelope, by listing only the names of the people invited. If you are not including an inner envelope then the persons who are invited should be listed on the envelope to the wedding invitation.
Whatever you choose to put on the invitation, add a little of your personality and set the tone for the event. A wedding is a celebration of love, regardless of whether it is the first time around or a second chance. Making sure you have the basics on your wedding invitation will ensure that your guests show up at the right time and place to help share your happy day.