Check this web site out. It has good information on how to get and apply for marriage licenses. There is a ten day waiting period for them and it is only good for six months. I would get the license anywhere from 3-6 months before the wedding. http://www.mnweddingminister.com/HennCoLocations.html
Having appetizers for a reception instead of a dinner also
might be a more inexpensive way to go. I would google "inexpensive weddings" or something to that effect. Check out the library as well, I am sure they would have books on planning MN weddings on a budget.
For flowers, you could check out Michael's or Joanne Fabrics and find some really nice silk flowers or something instead of spending money on real ones (way expensive!!). I also know that a lot of my friends spent alot of money on photographers that were awful. If you have a relative or friend that is really good a taking pictures, ask them to do it or give everyone disposable cameras to use.
If you need a wedding dress, look in the phone book for bridal shopes and there should be a little section on bridal consignment shops. My friend is getting married in 6 weeks and found her dress at one and it was under $500 for the dress and the alterations. The consignment shops have dresses that have been worn once and look like new and are only 3 or 4 years old so they are still in style. Also, keep on eye on David's Bridal, a few times a year they have a $99 sale (one is going on right now). If you are planning on wearing a veil, make it yourself. Check out this site as well:
http://www.wegotgame.net/jen/veils.html.
Invitations you should be able to do your self. Look up the Paper Depot in the phone book. You should be able to buy in bulk and I have heard good things about that place. Especially with the computer programs these days, you shouldn't need to spend a lot of money on them.
Go online and register for The Knot. It is a site devoted to weddings, although most things they recommend are pricey, it is good for ideas and they have a Q&A section.
I hope this helps!! Good luck!
PS Just remember - the planning is supposed to be fun and things will go wrong...as long as you remember that, you should be fine!!