Here's the problem:
It costs money to host pictures, as whomever owns the server that they are on has to pay for the bandwidth for each time that picture is downloaded (it is downloaded at LEAST the first time it is viewed, on each computer it is viewed on). So, if a 1 Meg picture is viewed by 1000 people here, that is at least 1 gigabyte of data that someone had to pay to transfer though to the Internet.
Given the above, most of the "free" web hosts will "turn off" linking to your picture after a certain number of hits, or they won't allow linking at all. The best, most reliable solution is to get a PAID account somewhere.
I should point out that joining AR15.com gets you some guarenteed picture hosting space. But, there are other options, such as [url]www.photopoint.com[/url], which will cost $30 a year, and is easy to use.
Wherever you upload to, you need to have the address that will display ONLY your picture, with nothing else around it. Then, you need to remove the "http://" part off the front of the address, and add the [img] [/img] tags around the address. In this example, I'll use curly brackets {} instead of square brackets, so you can see what I'm typing:
My address bar says this:
http://albums.photopoint.com/j/View?u=1130110&a=10062068&p=33632032&Sequence=0&res=high
By removing the "http://" at the beginning, and adding the tags, it would look like this (but with square brackets):
{img}albums.photopoint.com/j/View?u=1130110&a=10062068&p=33632032&Sequence=0&res=high{/img}
And when I replace the curly brackets with square brackets, you see the pic:
[img]albums.photopoint.com/j/View?u=1130110&a=10062068&p=33632032&Sequence=0&res=high[/img]
-Troy