Glad you stopped in - I love getting new designers to come by and show off their goods!
There's two ways to get an image into a post. You've learned the first way - uploading. 5 images per post, 1 Mb size limit - enough for huge images.
The second way is the BBcode command IMG. It works like this - but instead of ( and ), you would use [ and ].
(img)http://wherevermyimagelivesonline.com/image.jpg(/img)
Some people get fancy and use size parameters and such - I never bother. This is simple - why complicate things?
I never stop people from using IMG, but I do prefer uploads. Links have a habit of breaking over time, and we lose a lot of imagery that way, decimating some once-interesting topics.