There are threads that discuss the use of a serial monitor. Use the search box at the bottom left of this web page and type in "serial monitor". Also, consider using an OSBDM cable to do the deugging. They are inexpensive, and even if your shipping product will not have a BDM connector, the debugging capabilities of the BDM interface should help you debug your code faster. This is all based on the fact that I do not know what part you are targeting, or the toolset you are using for development/debugging work.
---Tom
