I have photoshop and I have the skills, but I have no idea how to make a theme and I can`t find any resources on how to do so. Can anyone please point me in the right direction? Thanks

You need to know CSS and XHTML. To make a new theme, go to manage themes in the admin panel, copy the main theme, and modify it as you wish. You should also create a directory in your images folder for your theme. To add custom HTML and to modify your layout, go to manage templates, clone one of them (for a base), and modify it as you wish. Make sure you assign your theme to that template, though.
Putting it all together is not as easy as you might think. It's not all Photoshop and replacing images.