There are plenty of free picture hosting websites out there, Webshots is one you could look at Pbase or Fotopic and if you keep you eye out as you cruise the other forums you will come across others.
Mr Brown uses Webshots and I used that as a recommendation and have several names to store my shots.
All very simple to load your shots onto there servers, although might not be a good idea to use them for safe storage, you'll need to back them up onto a DVD or CD at home.
When you come to use a shot on the forum, just be careful about the type, dimensions and kb's its all there for you. I use Photoshop Elements to re-size my shots and use JPEG, 500 pixels in width and 50kbs in size. all set through the "save for web" menu.
Come back for more help if needed, all the best, looking forward to seeing your shots.
FS