You can view field usage sorted by field, date, and time. This is particularly useful if you are trying to find open slots to schedule. Go to View Field Usage, define the date range, and choose a field. You can also view all games that have not had fields assigned by clicking on Field To Be Determined.

Note that games of other leagues on the same field will be displayed as well, if the other league is "sharing" the field with your league. Also, games on other fields that have a "sub-field" relationship (in either direction) will also be shown.