How do I check the alternator/rectifier myself. Could I use the voltage meter.
You're going to want to find the Haynes manual for your bike online (may take some searching...if you can't find one, I'll help you look)
You'll want a multi-meter with settings for Volts, Ohms, and diode/continuity testing.
Most standard multi-meters have these functions, and are easily and cheaply obtained from places like home hardware, the source, radio shack, etc.
Test the components using the known values and tolerances as outlined in the manual.
If you find this manual, MAKE BACKUP COPIES...it will be your best friend for as long as you own the bike!