I can't help you with that particular type of jacks, but you can perhaps find a manual for yours if you know the model #.
HWH Service Manuals
In general, use jacks in pairs so you don't twist RV frame. I.E.: 2 left side, two right side, two front, 2 back at the same time. Also, make sure you don't lift high enough to lift rear wheels off the ground, you'll lose the locking of the rear wheels' parking brake.
Happy adventures with your new RV!