ok thanks everyone, sofiel i'll try it out XD

ms paint works fine fo rme. i just use the polygon tool (shape thingy) and have it on the middle setting (shape filled in with outline, and black as the outline (first colour) and white as the fill (background colour)). you dont have to do the whole horse at once, cut it up into sections and erase the lines later on. of course, thats rendered linearts... might i suggest a graphic tablet? they are expensive, and you dont actually NEED one, plus it doesn't work very well with ms paint... but it can help you because you can draw more freely.
but i mainly art around, i only colour linearts for fun X3

Paint.net is better for linearts because it offers up the line too which makes it loads easer than just using the pen tool trust me! Gimp is better or effects, and backgrounds, and sometimes coloring in in the body of the animal you renderd. but Paint.net is perfect for linearts

I use GIMP for my renders, but if you don't want to install anything (I doubt you don't), you can use Animation Source's Sketcher.

i have a updated version of paint and gimp on my other computer ,to be honest i used to be terrible with drawing on computer but after practicing hard im now pretty dam good ,so maybe u should send some time practicing and also use others linearts with permission and u might star understanding how u need to draw (but im still rubbish at drawing horses

ok thanks

Paint.net and GIMP are what I am familar with, I personally use GIMP and there are alot of tutorials for it all over the internet (most include making lineart)