Datasheets

• MTK3329/MTK3339 command set sheet for changing the fix data rate, baud rate, sentence outputs, etc!
• PMTK 'complete' datasheet (like the above but with even more commands)
• Datasheet for the PA6B (MTK3329) GPS module itself
• Datasheet for the PA6C (MTK3339) GPS module itself
• Datasheet for the PA6H (MTK3339) GPS module itself
• MT3339 GPS PC Tool (windows only) and the PC Tool manual
• Sample code and spec sheet for the LOCUS built-in logger
• LOCUS (built-in-datalogging system) user guide
• Mini GPS tool (windows only)

More reading:

• Trimble's GPS tutorial
• Garmin's GPS tutorial

Adafruit GPS Library for Arduino

https://github.com/adafruit/Adafruit-GPS-Library/

EPO files for AGPS use

Data format for EPO files