For each of the properties in your template you can set a source for it, this isn’t always used but can improve user experience drastically when done throughout a site. The source field comes in to play whenever you are using any of the following fields: Droplink, Droplist, Droptree, File, Grouped Droplink, Grouped Droplist, Image, Multilist, Treelist, Rich text field and a number of others. There are various ways of setting these up to achieve different results – but in general you are using the source to limit the set of items that can be used, and this requirement can also help you determine what kind of field to use. For example, if you have a Set of items all split down into sub folders and want the content editor to make use of the tree, you could use a TreeList or Drop Tree, but if you just want a set of items without the opportunity to see where those items are – multilists or droplinks are the way to go. For Images you’re generally just specifying where to look for and put th...