* Cruise control on/off switch: This is usually located on the steering wheel itself, often part of a multi-function stalk. It's a small button or lever.
* Cruise control set/resume/coast switches: These are also usually located on the steering wheel stalk along with the on/off switch.
To locate these, look carefully at your steering wheel and the stalks coming from it. There's usually a stalk on the left side (from the driver's perspective) that controls things like turn signals, wipers, and often the cruise control. The cruise control functions will be clearly marked with symbols (often a car with a line underneath, representing speed).
If you're having trouble finding it, a look at a 1994 Ford F-150 owner's manual would be helpful. You can often find these manuals online as PDFs.