Your invitations are the first impression guests get about your wedding, so take time to get it right. Look at sites selling invitations online and in magazines such as Wedding Ideas as they can provide inspiration. You will soon learn what you do and don't like.
As a graphic designer and someone who pulled out all the stops designing her own wedding invitations, believe me when I say you can make DIY wedding invitations as simple or as complicated as you want. A lot of people go into making their own invitations hoping to save money, but I'll tell you up front: there are plenty of affordable places to get nice invites with less work than it will take you to DIY wedding invitations. However, if you have specific reasons to go DIY on your paper (like, you want to bring your specific idea to life, or you want to get creative) read on. (Fun fact: Every APW editor DIYed their wedding invitations, so we've got your back here.)