Open your program and click the “tools” pull down menu.  Click “options”, when the box comes up note there are quite a few tabs at the top of the box.  Click the “signatures” tab.  There may be some areas of this signatures area that are check boxes – if you want the statement to apply, click in the box to the left (checking it).  If you want to utilize an automatic (where you don’t have to add it each time), click the box to the left of add to all messages (specific text may vary with version).  Toward the middle of the box should be an area that has buttons on the right of it.  If you want to add a new signature, click the “add” button.  This should allow you to click in the bottom box (under edit signature) and place your signature text there by keyboard.  Once you have your signature text in (I suggest no more than 4 short lines), click the “set as default” button to the right.  Next, click the “ok” button at the bottom of this window.  It will close and the next time you send (new) mail, your signature will appear in the blank message before you begin writing.