Sure, but you don't have to worry about being a noob. We were all noobs once, even me.
But don't tell anyone! (uh oh!)
Anyway, just go to imageshack.us, and upload the image. You'll get a list of different links, but click "+Show Advanced Linking," and copy the url (should end with .png).
Then, when typing your post, paste the url in, highlight it, and click the "insert image" button. Then you should be good to go!