Upload & Sell: Off
Your pictures look good
About .tiff. Tiff files are huge because you lose no data. .jpg files are compressed, the amount of compression is based upon what you set. If the compression is too great, you will see artifacts. The greater the compression, the more data is lost. The less the compression, the more data is saved but the bigger the file.
If you are going to print, you want ALL the data. The printer can see more colors, I believe, than most monitors. Save in .tiff. Here is where it gets confusing. If you now want to display on the web, you always save as .jpg and throw data away. You don't get something for nothing.
It's also more complicated than that. You want everything from camera to monitor to printer to be in the same colorspace. I would ask in the printer forum.
Bottom line. It doesn't matter. Since you're converting to jpg for the web, it is what it is. To print, you want all the data. Save in tiff.
That is how I understand it, but, of course, I could be wrong.
Btw -puffins ... cool nice ...