10 years ago my husband and I got married - we planned the whole thing ourselves, and split the cost w/both sets of parents, but we wanted to keep the whole thing under $15,000- which is pretty miraculous from what I've heard. I found a book called "1001 ways to save money and still have a fabulous wedding", which was VERY helpful. You can probably find some great books at Half Price Books that can help you plan. Online wasn't really an option for me at the time.
Several helpful things - get referrals from married friends and/or parents of married friends - we found our caterer (a bargain!), our wedding location (another bargain), our photographer (another bargain) from friends. And if any of them have been "passed on" from friend to friend, you may be able to get a better deal because of that, because the vendor knows they will continue to get business from the chain of friends.
Have friends give you their expertise (or a nice discount on it) as wedding gifts. Does someone sew? Perhaps they can make the bridesmaids dresses, etc. My maid of honor bought the flowers (daisies-bridesmaids, roses-me). Friends decorated the venue with ivy and flowers from each others gardens.
Late morning/early afternoon - usually less expensive - we had a lunch menu, buffet style, worked fine.
HAVE FUN - make the wedding something YOU would enjoy, not just what's typical. My husband and I met Scottish Country Dancing, and took Karate lessons together when we were dating - so we had a dance and karate demo at our reception - we had an outdoor wedding/reception so it worked out really well. Friend still talk about it till this day, and we see our wedding favors (Frog squeak toys - e-mail me and I'll tell you the story) sitting out as decorations 10 years later.
Also, I didn't have a "dream" cake, or "dream" dress going into it. That way, I think I was able to be a lot more relaxed about things. I just wanted to be beautiful and have fun. Try to have a relaxed attitude about what you want from the day, and you will truely enjoy it!
I hope that was helpful! Sorry it was so long! Feel free to contact me if you want to :) Enjoy and congratulations!