I can't figure out how to upload a image and I'm too afraid to ask so I'm going to spell it out for you(sorry).
S- Eevee, Umbreon Shiny, and Jolteon.
A-Every Other One except...
F-Shiny Espeon and Jolteon, Because Lime Green is not fun.
With a file saved on your computer
Click "Use Full Editor" (next to the "Post" button), then the paper clip. (May look slightly different, depending on your layout and device.)
Attachment Paper Clip.png
Choose "Manage Attachments". Brings up a new window. Hit "Select Files". Locate the image you saved to your computer and hit "Open". Should see it under the "Manage Files" of the new window now.
Close the attachment window. Select the paper clip again. Should see the file.
Attachment Paper Clip 2.png
Click it to insert it into your post. Comes out something like:
[ATT ACH]99847[/ATTACH]
(Except with "Attach" as one word. Broke it up for this example.)
With a link
Same steps as above until the "Select Files" button. Go to the "Copy" tab instead of hitting the "Select Files" button. Paste your link into the field. Hit "Upload".
Close the attachment window. Tap the paper clip once more. Ought to see your file. Click it to insert it. Appears with the ATTACH tags around it, as above.