Most as Rick mentions post photos direct in their posts. You can load serveral at a time, not just one at a time. Not sure what the limit per post is, but you will soon find out if you try to post to many at once.
What I tend to do is start my post, then upload all the pictures I want to include. Move the cursor to where I want the picture to sit and then click on the "full image" button where the images are show after up-load.
I think the limit is ten photos per post, after you have uploaded ten to the thread just create another post if you want to add more photos.
One of the attractions of this site is the ease of posting photos, no third party hosting required.