TI has provided many tutorials for getting started with CCS. Finding one you understand can take a long time. I think this one may be more helpful than some of the others: http://processors.wiki.ti.com/index.php/Blink_your_first_LED. It covers installing CCS, creating a project, writing code, and programming the LP. I think it is simpler than the CCSv5 Getting Started Guide or the Getting Started with the MSP430 LaunchPad Workshop, so you may want to start there and go through the others after.
CCS provides the pin outs, register declarations, etc. in the header files that get included whe