You can go to http://photobucket.com/
And sign up for free with a username and password.
After log in, upload photos is very straight forward:
You can "Drag and drop" or browse and chose photos to upload.
After you uploaded a photo, every time you open it,
You should see few codes in a square on the right hand side.
Click on the "HTML code", and it would turn into "copied".
Now,
Just paste this code in your post,
And after you post it, this code would actually be seen as the photo you uploaded.