I would say start by getting comfortable moving the puddle on stainless steel. It is really easy to fuse stainless, so just take 2 pieces and but them together. Start your puddle and move down the seem. Once you can fuse together 2 pieces with good color, work on adding filler material to it. Stainless requires less heat then mild steel, and you have to move faster to get good color out of it. I'm no expert tho. Just practice a lot and post some pictures. Pictures are worth a thousand words as they say.
Justin