I’m probably not the guy that should be answering your question since I haven’t actually uploaded any photos yet, but I also know how frustrating it can be when you don’t get an answer to your question. I’ve done a LOT of searching and reading on here about photos, have been involved in a couple threads about photos, and have exchanged personal messages about photos so maybe I can at least give you the basics as I know them to be.
There are two different places where photos are involved on this forum. One is in threads, or discussions, in the forum and the other is in the “Gallery”. Uploading to the Gallery is pretty straightforward. First, login (obviously), then click on Gallery in the black menu bar near the top of the page. You’ll see two different choices, the Scale Auto Gallery and the Scale Auto Diorama Gallery. Choose whichever one you want your photos displayed in. Regardless of which you choose, you’ll see a red banner with the words, “Submit a Photo to this Gallery” in it. Click there and you’ll be presented with the actual upload page. The first step is to select the photo from your hard drive. Note that only JPEGs 3MB or less can be uploaded to the Gallery. Then just put in a name and description for the photo. Tags are optional and are just words that are used for searching. Then click the red, “Submit your photo”.
If you’re wanting to insert photos in a thread/discussion, you’ll first need to have someplace outside the forum to upload your photos to. I know a lot of guys use PhotoBucket. I’ve also heard that PhotoBucket seems to have some trouble at times. I’ve decided to use Fotki. It’s not a free site, but it seems to have a very good reputation so figured it was worth the expense, especially since I’m an amateur photographer in addition to getting back into building kits. Depending on where you end up hosting your photos there will be similar, but slightly different, steps to upload your photos to your account. Once you have your photos on your hosting site you just have to insert the URL to the photo into the thread. It sounds really confusing, but once you’ve done it a couple times it really clears up a bunch. It’s not nearly as difficult as it sounds.
Hope this helped a little. Maybe somebody else can chime in here and offer additional help.