You can go to
www.tinypic.com click on browse, select pic from your computer. Under resize, choose message forum for just posting a pic or thumbnail for signature pic, if you want a little bigger than a thumbnail, then use website size to get the size in my sig. Then click upload. Enter the anti spam code. When the codes pop up copy the correct url that will have an img code similar to the one MrMike gave you. Come back here, paste code in your post to just post a pic or if making a signature, you will need to go to member control panel, choose edit preferences and paste the code into the signature box.
I will usually save my codes in a word document on my computer so I can have easy access to it later.
Edited by: anaro