Hey,
Most of the new people don't know how to add signatures to their profile. So I'll make a guide how to add them on to your profile.
Step 1.) First of all click the "User Control Panel" button on the top-left of your page.
Step 2.) Then click on the "profile" button.
Step 3.) Now click the "Edit Signature" button.
Step 4.) Now you have to take your Image Url. That is the Link on the image that you want to add. Then you have to select the whole url until it is blue like this:-
Step 5.) After selecting the URL you have to click on the "IMG" Button.
Step 6.) Once you have done that the URL should look like this:-
Step 7.) The last step is to click on the "Submit" Button.