Step 1: Upload from your camera/phone. (Many smartphone apps allow for instant uploading to a host site right from your phone!)
Step 2: Find a hosting website:

(Using as an example)
Step 3: Create your account
Step 4: Click UPLOAD
Step 4: Click BROWSE FILES and pick your desired image to upload
Step 5: Click LIBRARY
Step 6: Click on desired image
Step 7: Copy IMG CODE text on right side tool bar under Image Links
Step 8: Paste newly copied IMG CODE text into your post

IF THERE ARE NO IMG TAGS (Instead an image's direct link)
Step 7: Copy the image's direct link
Step 8: Click on in "reply to post" toolbar
Step 9: Paste the image's direct link into box
Step 10: Click OK

Your image should show up in your post like such:

Congratulations. You now know how to host and post your very own pictures.

Now Go Post Your Newly Uploaded Photos!!

Quoted from PBN Thread.