Most on here use Photobucket.com, make an account, follow the instructions. It's turned into a bit of a popup monster these days but I think most image hosting sites are the same (unless anyone knows better)
Or you can just upload pictures to the firum, you might have to crop them down a bit because they display full size (so my digicams pics at 4000x3000 would take ages to upload and you'd only be able to see half of them. 1024x768 seems a good size.
If you reply to this post you should see 2 tabs under the text frame - "Options" and "Upload attachment". Click on "upload attachment", "browse" for the file on your computer, double click it or hit "Open", it'll then take you back here, click "add the file". It should then upload it. It then says "place inline" or "delete file" so click "place inline" if you want a link to your picture linked from your post
DSCN0725.JPG
, or alternatively, right click the filename of your picture, "copy link location", hit the image ("Img") tabs up there
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and paste the link inside them.
SOunds a bit involved but it's not really, once you've done it a few times it's easy.