Hi there.
I'm not sure if I put this question here or not.
I was trying to upload images to my follow along thread but if I use"Insert image"(From computer) button, then I get error message(through preview mode)
Is there a way to upload images correctly?
[IMG]http:www.urlhere.com[/IMG]
That should work 
I always upload to imgur then use the image button > insert URL, which will do what fabian showed.
The image upload usually works, not sure what's up in your case.
I'm uploading image to imgur about an image in imgur 

Anyway, after you upload, just copy the BBCode (message boards & forums) url, this is the most common tag used in most of the forums.
After that, you can just paste it in your post.
By the way, I use LightShot, my favourite screenshot tool.
It's faster for me to find an image, open it (second screen), hit Print Screen and select most of it > Ctrl+D > click open when done uploading > click/drag image to URL > copy URL > insert image in post.
Sounds more complex but doesn't require me to go to imgur or drag/drop into my browser and I continue doing stuff on my main screen while most of this is happening.
^^ that's handy! Thanks for the tip.
As for this steps "click/drag image to URL > copy URL" maybe it's faster by right clicking the image, and copy the image location / url. Dragging is a bit too far 

I tend to just click'n'flick it into a new tab then go back to whatever I was doing, then get the URL when I need it (this way I can spam half a dozen screenshots tabs in quick succession).
Gotta use those FPS muscle memory skills!