One of the biggest wedding-planning challenges can be cohesiveness — presenting a consistent vision for your event from start to finish. As a wedding planner, I see brides (especially those who are newly engaged) struggle with this all the time.
The most obvious question is how many attendants to ask and who should be your maid/matron of honor. What's important is that you include those people to whom you feel closest. Also consider where you'll be standing at the altar or huppah, and how many people can fit on either side of you.