To edit your signature, click on your name, scroll down to the bottom. There should be a section called "signature in the fourm" On the right, there should be an Edit button.
As for printing out, consider keying your encounters to an index, using either dice or a deck of cards as a randomiser. When play-testing, it's considerably cheaper (and less time intensive) to print out a word document or pdf than to print out individual cards. Once you're settled, then you can build the encounter decks.