Phil - nice pics and boas. Your new camera takes good photos. I'm sure there are several ways to make the pics bigger, but here's one way. If you have windows XP you have the paint program. Go to accessories and find paint. Open your pic in paint and go to image, then stretch/skew. Your pic is 600x361 pixels and kingsnake will let you go up to 1200x1000, so enlarge it to 200% and save the new larger pic and upload that to kingsnake.
I also use adobe photoshop and you can set the size to any dimension you want, either percents or actual pixel dimensions. It also allows you to decrease the total megapixels as kingsnake will only allow an upload of 450 KB and some of the pics will need to be decreased.
Another option is to use the free website photobucket.com. They automatically resize the pic for upload. They also give an IMG to the pic which works well if you want to post several pics in the same post. Hope this helps. Mark