How to Post a Picture using Attachments:I'm the un-techiest poster ever so this is really "Posting for Dummies"!
First, find a picture you want to share then:
Right click on the picture.
Left click on "save picture as"
That should take you into your computer's "My picture" site.
(I like to use the thumbnail setting --very top right tiny icon.)
File name will be highlighted in blue--leave it or change it to something you will remember.
Click on save. Picture disappears into your "My picture" file.
Now go on off to the forum...
Hit "reply"
Type your message.
Look at the lower left where it says additional options and click on that.
That opens a box that says attach: with browse and more attachments to the right of that.

(If you want to post more than 1 pic, click on more attachments first--you can open up to 5 boxes at a time)
Click on browse--that should open your own saved picture file (here's where the thumbnails come in handy because you can see the pic you want).
Scroll down till you find the picture you want and click on it (that enters the file name in the box).

Click on "open". That takes you back to the forum reply page and the Attach: box will be filled in...
Click POST and you are done!
Disadvantages? You can't preview your post /pictures once you do an attachment (you can if you publish them to the web), so I usually preview my typed message before I add the pics. And sometimes the pics are too large and you have to resize them (there is a total limit of 256KB and 5 pics per post). And you can't put a label or comment above each picture separately like you can when you publish them to the web.
Advantage? For me it is speed--I can find/save/post a pic in no time flat now--very helpful when we are in a rush!
Puddin does tell me that this method uses more bandwidth than the "real" way, and that therefore Rob cleans house every six months or so-- so your prized picture post may disappear. So pictures that you may need later for reference would be better posted using the upload technique.