Well the thing is, I don't know how to use Photoshop, I've used Paint.net but now i really want to use Photoshop, Could someone please give me advice / tips that might help?

Thanks!

errm, we can't just tell you what to do because PS is a huge application with a huge amount of features and tools. The best way is to get a good photoshop for beginners book to learn the basics, then find some kind of photoshop magazine that tells you step by step how some photos are made (in Belgium that is Advanced Photoshop magazine if I'm not mistaking) and if that's not enough you could try to reproduce pictures (but that's hard if you don't know every filter and the outcome of those filters)

Agreed, this is like saying that I have done finger painting and now will you show me how to paint the Sistine chapel? Compared to almost any other paint like application Photoshop is an entirely different animal. Basically put it is what the professionals use and there is a reason they went to school for graphic design for four years.

In my opinion, one of the key features of Photoshop is layers. You are not constrained by just one sheet but you can combine and interact with multiple layers to create some really nice effects. Another feature that I use all the time is the layer effects such as glow or drop shadow. I never did get the hang of using the pen tool but I have seen really great things done with it. My advice is to ask a specific question and then get some feedback.

I think for me to help you, you would need to narrow your question into some form in which we can answer. To ask use to help you on how to use photoshop is like asking to teach you kung fu, in which there are many forms and styles. Just like photoshop, there are a ton load of stuff that you can do with it whether it be image editing, texture creation, image automation, web design, graphic optimization, icon creation, vector art, and so forth. But if you want to learn how to do some cool stuff with photoshop from the start with out learning the basics I guess you could just do a google search on "photoshop tuturials." That would probably be your best bet, then if you have issues or problems that you cant resolve in the tutorials than you can come here and ask us. But otherwise, we cant help you if you cant help yourself into refining your question into a more specific form. Once you learn photoshop you creativity of graphic arts will probably be immersed in a form in which you cant get through painting or drawing on canvases. This form of art in photoshop basically pushes your artisitic skills to its limits, and eventually you will learn where your limit lies, I certainly notice a difference when I mastered the program, but I also now know my limitations compared to other peoples work that I have seen. Its not that I couldnt do what they do, but to come up with the idea first is where things gets interesting. Take a 2d image and making it into a 3d almost reality picture is where my ability have not been able to grow to yet. But I know with practice I will eventually get there, but from the works I have seen online, the competition out there is very large, and your ability and talents must be very great if you want to compete with the best of the best out there in the world.