text sig rocks
but if you want a bit of graphical elements in it then I suggest as small as possible. I kinda like wide sigs with height like 10-25px. No matter what you'll decide try to go original. Don't just copy an idea from someone, think about it yourself and then try to create it. We are more than happy to help you if you need any help. It's also a good idea to consider the website which the sig goes into so it kinda blends in.
Almost forgot to say hi and welcome. I'm sure you'll enjoy your stay in here.