Hi John,
Welcome to the site. It's probably best to read the FAQ section here: http://www.airlinercafe.com/plug.php?e=faq as it covers everything in detail regarding where and how to upload photos.

You can upload your own Avatar from your profile page as long as it is less than 150x150 pixels and no more than 8KB in file size.

If you still need further help, please ask.

Hi John,
Ok, I thought you meant one of the galleries, I have to read more carefully.

Basically you go to the PFS section by clicking on "My files" from the white links in the user bar. You can actually upload images right there, but I wouldn't recommend that as it will get very messy after you have a few dozen images uploaded. So, scroll a little down and create a folder first. Create one with the desired name and description, like "Images for Forums" for example. After you have created the folder, select it from the drop-down menu and then upload your images into that folder. Be sure to select private and no for the gallery option. This way, no one else will see the photos until you insert them into a forum post. Be sure to keep the photo dimensions and file size in mind, at the top it will also tell you how much space you have for uploading photos.

After you have uploaded all the images into the appropriate folder, when you are writing a post in the forum, at the bottom left of the text area, you will see a link titled "My files" again. Click on that and it will open a pop-up to your PFS. There, you will see the links to the photos and a green or blue icon at the end. If you click on the green icon, it will insert a thumbnail that is automatically linked to the actual photo, if you click the blue icon, it will insert the full-size image right in the forum post.

That's about it. Yes, you probably do have to play around with it a bit till you get the hang of it. It may seem a bit difficult at first, just keep trying and you will get it. If you have any more questions, please don't hesitate to ask.