For weddings, there are certain things that you can DIY and other things that you should entrust to a professional. At least in my opinion.
I'm totally into DIY, and for my wedding, I chose certain things to DIY. I did the invitations, escort cards/favors, and table numbers.
This display is actually from the New York Gift Show, and Sweet Bella used it to show off their collection of Japanese masking tape. At first I totally thought it was an escort card display. It's totally DIY friendly. I think I'd choose a couple of tape colors that compliment your wedding colors -- OR if you need a way to show which guests receives which plated meal (beef, chicken, fish), this would be perfect!
Photo by The Haystack Needle
On the other hand, there are definitely areas to hire a pro!
Hire a pro:
Photography - Please, hire a professional. I've heard far too many horror stories of couples either asking a friend or a relative to "snap" a few shots. And then being terribly disappointed. Or, hiring a really inexpensive/inexperienced photographer and being disappointed.
Flowers (unless by trade you are a floral designer, of course) - I've seen DIY flowers gone awry. I've spoken to a few floral designers in Dallas and many of them can help you maximize the flowers based on your budget.
Invitations (unless you know what you're doing!) - I DIY'ed my own invitations. I was very happy with how they turned out, however, I think that I lacked a good eye for design. If I were to do it again, I think that I would hire a pro for the design, and then assemble them myself. I think that could be a good compromise between hiring a pro and DIY'ing them.
DJ - I have been to the iPod wedding. Save yourself and your wedding party the headache and hire a DJ. If they are good, they are totally worth the investment. A good DJ will get the party going and encourage guests to get on the dance floor, without being annoying.
Above all, before you dive into the wedding planning process, sit down with your fiance, parents, or whoever is paying for the wedding and figure out your budget. Then prioritize what is most important to you - photography, videography, flowers, paper, etc. This will help you figure out how and where to spend your money.