A budget is very important, especially if you are spending someone else's money (your parents, or possibly your fiancé's parents). Here is a basic list of what you should put in your budget and the average percentages of what brides spend in each section. To figure out your amounts just take your total budget and times it by the percentage listed. Example: $20,000 budget, Reception Location 9%, $20,000 x 9% (or 0.09) = $1,800. So, you should spend approximately $1,800 on your reception location.

Ceremony Fee 2.5%
Ceremony Decorations 1.5%
Reception Location 9%
Reception Decorations 4.5%
Food and Service 33.5%
Beverages and Bartender 9%
Cake and Cutting Fee 3%
Wedding Gown 6.5%
Veil and/or Headpiece 1%
Bridal Accessories 1%
Hair and Make-up 0.5%
Massage, waxing, facial, etc. 0.5%
Bouquets/Boutonnieres 2%
Band/DJ/Orchestra 6.5%
Photographer 6.5%
Videographer 5.5%
Invitations 4%
Car/Limo Rental 1.5%
Wedding Favors 1.5%

Obviously, everyone will have personal preference as to what they want to spend on different things. You'll need to go through the budget after you have calculated the amounts and figure out if you think any are too high, or too low. You can then spend accordingly!