Google brush tutorials or check
www.good-tutorials.com or
www.pixel2life.com. Let me tell you one thing first: Do NOT use filters, and then call it a piece of art. You'll only look like an idiot in many people's eyes. Filters in Photoshop are there to enhance whatever you are creating (either by blending the layers, or changing opacity's), filters don't create art for you.
On that note, I won't jump on the bandwagon like all the other people, and I'll just be honest. They suck, from an artistic point of view. It's great to see you delved into the pits of Adobe, but before you have anything 'noteworthy' to show, you still have a lot to learn. So I would really advise you to check the above websites for some tutorials. Like I said, find Brushing tutorials, find signature tutorials, find wallpaper tutorials. Learn from them, combine them, create something unique and different. Challenge yourself to become better. And when you are trying to achieve something, but you don't know exactly how you should go about doing it, come back here and maybe some of us will be able to help you.