Hi, and welcome. Can't wait to see the images of your Begonias.
When you look up a plant, and find the entry in our Database, then click on the name to go to the page, you just need to scroll down to the bottom of the page (which is sometimes below the ads) to the section labelled "Adding actions" where there is a link to upload a photo.
On this (Ask a Question) forum, what happens when you click on the button at the bottom of this text box that says "Upload an image" ? It should give you an option to browse your photos, and just click on the one to upload.
