I use Photobucket...If there is a pic below, then read on ('cuz then I must be doin' it right!)...
You go to
photobucket and you 'join free' by simply entering a username and a password.
Now you have a place ON THE WEB not just on YOUR PC to store pics. You will be uploading copies of your camera pics stored on your PC. When uploading copies of your PC pics into photobucket, the process is very much the same as attaching pics to emails.
Photobucket will give a unique web address (or URL, or link) to each pic you upload; for instance, cut and paste this link into your browser and see what it is:
http://i166.photobucket.com/albums/u110/burlmart/HPIM0426.jpg
With a web address, each of your pics are now poised to be inserted into a forum post (as I did in this post) using the 'image' icon on the toolbar of your RV.net message editor. The image icon window opens and asks for the URL (= web link or address) of a pic, and you give it one of your photobucket pic URLs like you cut and pasted above.
This is the best explanation I can muster...I DO hope it helps!
2005 Trail Lite 213 B-Plus w/ 6.0 Chevy