Hmm,
I like your work,
For a bigginer you arn't half bad, although try and branch out, create new things, it gets boring for the creator and the viewer if you make the same things.
The style of most of your sigs have either been attempted or made already,
another reason to make something new.
I personally reccomend tHs's tutorial - viewtopic.php?f=31&t=27002
It will get you kick started on the road of art!
Good luck, Hope to see you around the forums!