I totally get it, ordering online can be iffy if you don't know how the style will fit! Although all pants are made a little different, this is a general guideline for where to measure on yourself and also a pair of jeans to figure out the best fit for you. Grab that measuring tape (the floppy kind) and lets go!
WAIST: Measure where your natural waistline is, usually below your navel.
HIPS: Stand with feet together and wrap measuring tape around the widest part of your hips.
RISE: The top of the waistline to the fork of the trousers.
INSEAM: For of the trouser (crotch) down the inside of the leg.
THIGH: Wrap around the fullest part of your upper leg.