It is really pretty easy now with the latest versions of iOS, LR Mobile, and LR CC. RAWs to the Camera Roll by card reader or camera app, create new collection in LR mobile and add the RAWs, edit now or later. When the RAWs are added to LR mobile, they will be sync'd to your desk top, and the full resolution RAW will be added to the desk top as well (the exact location depends on your set up). This can take a while depending on the number, the file size, and your wifi speed (my 20 megapixel raws typically take 5 min each), so you may have to let it run overnight.
There are a number of instructional videos available on YOUTUBE.