Hey, can anyone please teach me how to do a digital drawing, or change the backround of a picture? Please please please
Digital drawings usually use a tablet, as they are hard to produce using a mouse, but I know of some people who use a mouse and they work just fine, I can't though. =/ I'm sure someone can help you with that!
I can help you out with the background changing though, or at least try. =)
If you want to cut out a single horse, or a few horses or whatever, first of all, create a new layer being transparent, and then drag it beneath the other layer in the layer window, then on the main image layer, right click, and select 'merge down' that'll make your image easier to select alone when you start cutting out the background or whatever.
To cut things out I use the magic wand tool and the lasso tool as they're called in PS(I use gimp like you do but call it the same), they're in the top row in the tools. Here are the keyboard shortcuts for GIMP:
Hot Keys for GIMP:
Ctrl + c = copy
Ctrl + v = paste
Ctrl + x = delete
Ctrl + y = redo
Ctrl + z = undo
Ctrl + shift + a = unselect all
Ctrl + a = select all
After you have merged down your picture onto the transparency layer, you can use the lasso tool, and basically 'cut out' an area that you don't want, making sure that the end of the selection is right with the start of the selection(you'll see two circles on the end of the line) the lasso tool is basically a selection and a deletion tool. And from there you can remove a background, and then create a new transparent layer, and move the layer behind(down) from the main layer with the image or selection you are working with and paste a new image or background in behind the image on the new layer, making sure that when you paste a new layer in, that you merge to image or whatever the selection is when you right click on the layers.
One more thing, if you place an image on a new background, make sure to take the blur tool, and take the intensity down a few notches, and smooth the edges a bit on the main image, it'll help maintain a 3-d look. Practice will help a lot though. =) I can try to go into more detail if you need it, but I think that covers the basics for that. =)
Hope that helps, feel free to ask more questions if I didn't answer something or I confused you. =)