As an addition to what Wes suggests, another idea is to create the symbology for all the types, make multiple copies of this, then remove all the types from each copy but the one you want displayed. Then repeat for each single item you want displayed, so you end up with multiple "layers" of the same data each only showing one item, which gives you flexibility on displaying the data.
Not an elegant approach (Definition Queries are preferred), but workable if all you want to do is easily display data without having to figure out queries.
To do so:
- In the Table of Contents area in ArcMap, right-click on the layer you want to symbolize.
- Choose "Properties..." from the list that shows up.
- Click on the "Symbology" tab.
- On the left, under "Show:", click on "Categories" and then select "Unique Values" (or "Unique Values, many fields" if that is more appropriate to your data).
- In the "Value Field" box, click on the pulldown and choose the field in your table that provides the differentiation.
- Choose a "Color Ramp" that looks good for your data.
- Hit OK. Now, to copy the symbolized layer, right-click on it in the Table of Contents and choose "Copy"
- In the Table of Contents, right-click on the word "Layers" and choose "Paste Layer(s)". Repeat as needed.
- To reduce the categories showing in a symbolized layer, first repeat steps 1-3 to get back into the symbology tab.
- Then right-click on the symbology that you don't want displayed and choose "Remove Value(s)" (or highlight it and click the "Remove" button).
- Under "Symbol", uncheck the checkbox by "<all other values".

Hit OK when done. Now one can use the checkboxes next to each symbolized layer to turn each layer on and off as desired.

Caveat: This method only works for visual display of the data. It does not limit the data in the table; the data table for each layer still has all the data. So if you want to know how many of a type you have, you will need to take additional steps to determine that.
Chris Donohue, GISP