For this example we'll use a PhotoBucket (PB) account.
1) Firstly you'll need to register yourself an account at PB - http://www.photobucket.com. That should be straight forward (I hope).
2) Once you've registered and logged in, you'll see the upload function at the top of the page. If you wish to upload several files at once, do so by clicking on the drop down box and selecting the number you need. Use the "Browse" button to locate the files on your hard drive.
3) Once you've located the files on your PC and uploaded them, they will appear in the album below the upload function. Under each image are three lines of text - links to the image. To post on this forum, you'll need line marked "IMG".
4) Copy the link from the "IMG" box, and paste it into a new post here. Repeat as necessary for all of the images you want to post. When making your post, make sure you hit return after each link you paste - this 'stacks' the image down the page.
5) Before you post, hit the preview button to make sure all your images are there, and that they're displaying correctly. If you're happy, post it!
Image sizes for the forum should be no bigger than 1024 pixels on the longest edge and file sizes less than 300KB each. To check the file sizes, you can use the "Save for web" function in photoshop, and use the slider to control the file size, or save at quality 9 or 10 in photoshop.