The gallery is fairly straight-forward, but if you upload a group of photos at once, it might get annoying if you don't know the tricks.
From the upload menu, you'll be able to upload either one or a batch of photos at once. Either drag and drop them from a folder onto the icon or click on the upload button to open the menu. That's easy, but after that... you'll get into the photo settings. Every photo must be assigned at least one category for general display and a title. I've found that the easiest way is to pick a category, then click on "use filename as title" then hit the "Apply to all other images" button, then scroll down further to finish the upload. If you want to get into more detail for a smaller batch, you can pick a category and click on the circle icon next to "Categories" to assign that to the rest of photos, then edit the others individually to assign detailed titles, descriptions, map locations, etc.
It's optional, but highly recommended that you use the album option for uploading batch of photos like from trail rides or modifications so you can find them or share them easier in the future.
After you've uploaded them to the gallery, you can post them rather easily into the forum. You'll only see this option if you have photos in the gallery. If you click on it, you can either post a whole album in a side-scrolling format (demo below) or individual photos. The side-scrolling album will only be possible if you used the album function when uploading, so another reason to use it.
This album demo is from a January 2006 trip to Rausch Creek.