Welcome Dan,
There are two ways to share photos here. The first is to post them to threads. The second is to post to the online database.
Posting to Threads
1) Make sure your cursor is in the edit box that is used to type messages. (voice of experience)
2) Click on "Upload and Image"
"
3) Select (click on) the file you want to upload (note that images not larger than about 800 pixels on a side upload pretty quickly bigger ones can be much slower)
4) Optional: click "Preview" to make sure it was uploaded correctly
5) Click finished
Posting to the Database
1) Click on Plant Database button in the main menu at the top of the page.
2) Type in the name of the cultivar
3) Select the cultivar from the list presented ( It may be a list of one item. Or it may be more.)
4) Find near the bottom of the page an entry called Adding Actions
5) Click on Upload Photo.
6) Find the photo file on your computer and select it.
7) Fill in the form describing the photo.
8) Hit Submit Photo button.
And thanks for asking. It's the first time I've posted to the database and I wanted to know how to do that, too.