Follow these instructions for an easy way to get up and going quickly! These are complete instructions, and will be the easiest way to get started on a new RG35XX.
Get a high quality SD (e.g. SanDisk Extreme) card, 128GB or larger, 256GB is recommended. Don't skimp here, they're cheap, and don't use the card that comes with the RG35XX as it's crap.